/* erkennen des Browsers und dann verstecken oder zeigen des Untermenüs */

var ns4 = (document.layers)? true:false;
var ie4 = (document.all)? true:false;

if(navigator.appVersion.substring(0,1) == "5" && navigator.appName == 'Netscape') 
	{var ns5 = true;}

var run=0;

function zeig(id) 
	{
		if (ns4) {document.layers[id].visibility = "show";}
			else if (ie4) {document.all[id].style.visibility = "visible";}
			else if (ns5) {document.getElementById(id).style.visibility = "visible";}
		clearTimeout(run);
	}

function lege(id,zeit) 
	{
		if (zeit==1) {id2=id;   run=setTimeout("lege(id2)",2000);} 
			else {clearTimeout(run);
				if (ns4) {document.layers[id].visibility = "hide";}
				else if (ie4) {document.all[id].style.visibility = "hidden";}
				else if (ns5) {document.getElementById(id).style.visibility = 'hidden';};
				}
	}
function leer() {       }


var preloadFlag = false;
	function preloadImages() 
		{if (document.images) 
			{	heimat_on = newImage("img/t/t.gif");
				sitemap_on = newImage("img/t/t.gif");
				beruf_on = newImage("img/t/t.gif");
				joke_on = newImage("img/t/t.gif");
				links_on = newImage("img/t/t.gif");
			preloadFlag = true;
			}
		}
		
function newImage(arg) 
	{if (document.images) 
		{anzahl = new Image(); anzahl.src = arg; return anzahl;
		}
	}
	
function changeImages() 
	{if (document.images && (preloadFlag == true)) 
		{for (var i=0; i<changeImages.arguments.length; i+=2) 
			{document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
			}
		}
	}

function oeffne(das) 
	{
		window.open(das,"Bild","width=650,height=500,top=10,left=50,menubar=yes,location=no,status=no,toolbar=yes,scrollbars=yes");
	}

function druck(das) 
	{
		window.open(was,"Druckansicht","width=650,height=500,top=10,left=50,menubar=no,location=no,status=no,toolbar=no,scrollbars=yes");
	}

function suchhilfe(was) 
	{
		window.open(was,"Hilfe","width=450,height=300,top=10,left=50,menubar=no,location=no,status=no,toolbar=no,scrollbars=yes");
	}

/* Das Beispiel 
so wird aufgerufen
<td>
<a href="javascript:nix()" 
	onmouseover="zeig('heimat'); hide('sitemap',0); hide('beruf',0); hide('joke',0); hide('links',0); changeImages('tagu', '/vdi/images/hauptnavi/M_Tagungen.gif'); return true" onmouseout="hide('tagungen',1); 
		changeImages('heimat', 'img/t/t.gif'); return true">
		<img src="../img/t/punkt_rot.gif" alt="" width="30" height="30" border="0" alt="" name="heim"></a></td>
so wird definiert
	<div id="heimat" style="position : absolute;left : 145px;top : 91px; z-index: 1; visibility:hide; visibility:hidden">
	
	*/