
function centerLayer( layerStyle , layerHeight , layerWidth )
	{
		var documentHeight = document.body.offsetHeight > screen.availHeight ? document.body.offsetHeight : screen.availHeight;
		var documentWidth = document.body.offsetWidth > screen.availWidth ? document.body.offsetWidth : screen.availWidth;
		var layerLeft = parseInt( ( documentWidth - layerWidth ) / 2 );
		var layerTop = 20;
		layerStyle.left = ( layerLeft > 0 ? layerLeft : 10 ); 
		layerStyle.top = layerTop; 
	}

function hideLayer( layerID )
	{
		var layerStyle = document.getElementById( layerID ).style;
		layerStyle.visibility = "hidden";
	} 

function hideContactLayer()
	{
		hideLayer( CONTACT_LAYER_ID );
	} 

function hideSitemapLayer()
	{
		hideLayer( SITEMAP_LAYER_ID );
	} 

function initContactLayer()
	{
		writeContactLayerStyle();
		document.write( '<div id="' + CONTACT_LAYER_ID + '">' + 
							'<table border="0" style="background-repeat:no-repeat;" class="' + CONTACT_LAYER_ID + 'Table">' +
								'<tr>' +
									'<th colspan="2">www.statik-lernen.de</th>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="10"></td>' +
								'</tr>' +
								'<tr>' +
									'<td width="100">Diplomand:</td>' +
									'<td>Tobias Renno</td>' +
								'</tr>' +
								'<tr>' +
									'<td rowspan="5"><img alt="" border="1" class="logo" height="40" src="gif/logo_fhkl_klein.gif" width="40"></td>' +
									'<td>Badstraße 36</td>' +
								'</tr>' +
								'<tr>' +
									'<td>66914 Waldmohr</td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="3"></td>' +
								'</tr>' +
								'<tr>' +
									'<td><a href="mailto:webmaster' + '@' + 'statik-lernen.de" onMouseover="return hidestatus()">webmaster' + '@' + 'statik-lernen.de</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="10"></td>' +
								'</tr>' +
								'<tr>' +
									'<td>Betreuer:</td>' + 
									'<td>Prof. Dipl. - Ing. Birger vom Ufer</td>' +
								'</tr>' +
								'<tr>' +
									'<td rowspan="7"><img src="gif/map.gif"></td>' +
									'<td>Fachhochschule Kaiserslautern</td>' +
								'</tr>' +
								'<tr>' +
									'<td>Fachbereich Bauingenieurwesen</td>' +
								'</tr>' +
								'<tr>' +
									'<td>Schoenstrasse 6</td>' +
								'</tr>' +
								'<tr>' +
									'<td>67659 Kaiserslautern</td>' +
								'</tr>' +
								'<tr>' +
									'<td>Fax: 0631 / 3724 - 555</td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="3"></td>' +
								'</tr>' +
								'<tr>' +
									'<td><a href="mailto:birger.ufer' + '@' + 'fh-kl.de" onMouseover="return hidestatus()">birger.ufer' + '@' + 'fh-kl.de</a>&nbsp;&nbsp;|&nbsp;&nbsp;<a href="http://www.fh-kl.de" target="_blank" onMouseover="return hidestatus()">www.fh-kl.de</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="20"></td>' +
								'</tr>' +
								'<tr>' +
									'<td align="center" colspan="2">' +
										'<input onclick="javascript:hideContactLayer();" onmouseover="this.style.cursor=\'hand\';" type="button" value="Schließen">' +
									'</td>' +
								'</tr>' +
							'</table>' +
						'</div>' );

		hideContactLayer();
	} 

function initSitemapLayer()
	{
		writeSitemapLayerStyle();
		document.write( '<div id="' + SITEMAP_LAYER_ID + '">' + 
							'<table cellspacing="0" cellpadding="0" class="' + SITEMAP_LAYER_ID + 'Table">' +
								'<tr>' +
									'<th colspan="2">Sitemap</th>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line0.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/home_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="home.html" onMouseover="return hidestatus()">Home</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/vorwort_active.gif" width="20" height="13" border="0" alt="">&nbsp;<a href="vorwort.html" onMouseover="return hidestatus()">Vorwort</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/geschichte_active.gif" width="16" height="15" border="0" alt="">&nbsp;<a href="geschichte.html" onMouseover="return hidestatus()">Geschichte</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="gesch_pers_davinci.html" onMouseover="return hidestatus()">Bedeutende Persönlichkeiten der Entwicklung</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line2.gif" width="16"> <a href="gesch_einordnung.html" onMouseover="return hidestatus()">Einordnung der Statik in der Mechanik</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/grundlagen_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="grundlagen.html" onMouseover="return hidestatus()">Grundlagen</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_kraefte_1.html" onMouseover="return hidestatus()">Kräfte und Kraftarten</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_a_i_kraefte_1.html" onMouseover="return hidestatus()">Äußere und innere Kräfte an Bauteilen</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_zentrales_kraeftesystem_1.html" onMouseover="return hidestatus()">Das zentrale Kräftesystem</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_momente.html" onMouseover="return hidestatus()">Momente</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_auflager.html" onMouseover="return hidestatus()">Auflager</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_zustandslinien_1.html" onMouseover="return hidestatus()">Zustandslinien</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="grundl_statische_bestimmtheit_1.html" onMouseover="return hidestatus()">Statische (Un-)Bestimmtheit</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line2.gif" width="16"> <a href="grundl_lastannahmen_1.html" onMouseover="return hidestatus()">Lastannahmen im Hochbau</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/beispiele_active.gif" width="15" height="16" border="0" alt="">&nbsp;<a href="beispiele.html" onMouseover="return hidestatus()">Beispiele</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_einfeldtraeger_1.html" onMouseover="return hidestatus()">Einfeldträger</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_kragtraeger_1.html" onMouseover="return hidestatus()">Kragträger</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_gelenktraeger_1.html" onMouseover="return hidestatus()">Gelenkträger</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_dreigelenkrahmen_1.html" onMouseover="return hidestatus()">Dreigelenkrahmen</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_fachwerk_ritter_1.html" onMouseover="return hidestatus()">Fachwerk (Ritterschnitt)</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_fachwerk_cremona_1.html" onMouseover="return hidestatus()">Fachwerk (Cremonaplan)</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_zweifeldtraeger_1.html" onMouseover="return hidestatus()">Zweifeldträger</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_gelenkrahmen_1.html" onMouseover="return hidestatus()">Gelenkrahmen</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_physlet.html" onMouseover="return hidestatus()">Physlet (Einzellast auf Einfeldträger)</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16"> <a href="beisp_flash_einfeldtraeger.html" onMouseover="return hidestatus()">Flash-Animation (Einfeldträger mit vertikaler Einzellast)</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td><img align="absmiddle" height="20" src="gif/sitemap/line3.gif" width="16"></td>' +
									'<td>' +
										'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img align="absmiddle" height="20" src="gif/sitemap/line2.gif" width="16"> <a href="beisp_flash_rahmen.html" onMouseover="return hidestatus()">Flash-Animation (Zweigelenkrahmen mit vertikaler Einzellast)</a>' +
									'</td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/download_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="downloads.html" onMouseover="return hidestatus()">Downloads</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/lexikon_active.gif" width="16" height="12" border="0" alt="">&nbsp;<a href="lexikon.html" onMouseover="return hidestatus()">Lexikon</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/links_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="links.html" onMouseover="return hidestatus()">Links</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/literatur_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="literatur.html" onMouseover="return hidestatus()">Literatur</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line1.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/about_active.gif" width="16" height="16" border="0" alt="">&nbsp;<a href="about.html" onMouseover="return hidestatus()">About</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2"><img align="absmiddle" height="20" src="gif/sitemap/line2.gif" width="16">&nbsp;<img align="absmiddle" src="gif/tabs/wetryharder_active.gif" width="20" height="16" border="0" alt="">&nbsp;<a href="wetryharder.html" onMouseover="return hidestatus()">We try harder !</a></td>' +
								'</tr>' +
								'<tr>' +
									'<td colspan="2" height="10"></td>' +
								'</tr>' +
								'<tr>' +
									'<td align="center" colspan="2">' +
										'<input onclick="javascript:hideSitemapLayer();" onmouseover="this.style.cursor=\'hand\';" type="button" value="Schließen">' +
									'</td>' +
								'</tr>' +
							'</table>' +
						'</div>' );

		hideSitemapLayer();
	} 

function initUtilities()
	{
		initContactLayer();
		initSitemapLayer();
	}
function isLayerHidden( layerID )
	{
		var layerStyle = document.getElementById( layerID ).style;
		return( layerStyle.visibility == "hidden" );
	} 

function isContactLayerHidden()
	{
		return( isLayerHidden( CONTACT_LAYER_ID ) );
	}

function isSitemapLayerHidden()
	{
		return( isLayerHidden( SITEMAP_LAYER_ID ) );
	}

function showLayer( layerID , layerHeight , layerWidth )
	{
		var layerStyle = document.getElementById( layerID ).style;
		centerLayer( layerStyle , layerHeight , layerWidth );
		layerStyle.visibility = "visible";
	}

function showContactLayer()
	{
		showLayer( CONTACT_LAYER_ID , CONTACT_LAYER_HEIGHT , CONTACT_LAYER_WIDTH );
	} 

function showSitemapLayer()
	{
		showLayer( SITEMAP_LAYER_ID , SITEMAP_LAYER_HEIGHT , SITEMAP_LAYER_WIDTH );
	} 

function toggleContactLayerVisibility()
	{
		if( isContactLayerHidden() )
			{	showContactLayer();
				hideSitemapLayer();
			}
		else
			hideContactLayer();
	}

function toggleSitemapLayerVisibility()
	{
		if( isSitemapLayerHidden() )
			{	showSitemapLayer();
				hideContactLayer();
			}
		else
			hideSitemapLayer();
	}

function writeLayerStyle( layerID , layerHeight , layerWidth )
	{
		document.write( '<style type="text/css">' +
						'#' + layerID +
						'{' +
							'background-color:#F5F5F5;' +
							'border:darkgray 1px solid;' +
							'font-size:11px;' +  							
							'height:' + layerHeight + 'px;' +
							'left:0px;' +
							'position:absolute;' +
							'top:0px;' +
							'visibility:hidden;' +
							'width:' + layerWidth + 'px;' +
						'}' +
						'.' + layerID + 'Table' +
						'{' +
							'margin:20px;' +
						'}' +
					'</style>' );
	} 

function writeContactLayerStyle()
	{
		writeLayerStyle( CONTACT_LAYER_ID , CONTACT_LAYER_HEIGHT , CONTACT_LAYER_WIDTH );
	} 

function writeSitemapLayerStyle()
	{
		writeLayerStyle( SITEMAP_LAYER_ID , SITEMAP_LAYER_HEIGHT , SITEMAP_LAYER_WIDTH );
	} 