// deze functie voegt in IE een extra class: over toe. 
// Dit is nodig om in IE het menu rollover goed te laten werken
 
startList = function() {

if (document.all&&document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+=" over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace(" over", "");
   }
   }
  }
 }
}
window.onload=startList;


<!-- Begin Preloaden Tabs RollOver

image1 = new Image();
image1.src = "tab_Inwoners_Ro.gif";

image2 = new Image();
image2.src = "tab_Politie_Ro.gif";

image3 = new Image();
image3.src = "tab_Bestuurders_Ro.gif";

image4 = new Image();
image4.src = "tab_Pers_Ro.gif";

// End -->

// Foto Rollover functie -->
function movepic(img_name,img_src) {
document[img_name].src=img_src;
}

// positie floating tab -->
// http://www.devarticles.com/c/a/Web-Design-Standards/Matching-div-heights-with-CSS-and-JavaScript/3/
function getHeight() { 
	var divToSet = "" ;
	var divToMatch = "" ;  
	var divHeight = "" ; 
	
	divToSet = document.getElementById('content_Right_Container'); 
	divToMatch = document.getElementById('content_Left_Container');
	
	divHeight = divToMatch.style.pixelHeight; 
	
	divToSet.style.marginTop = "-200";
	
	//alert (divToMatch);

}
     

     // get <div> element in the document 

    
	
	// document.writeln(divToSet)
	
	// get height of divToMatch
	
	//if(divToMatch.offsetHeight){ 
    //      divHeight=divToMatch.offsetHeight; 
    //    } 
    //else if(divToMatch.style.pixelHeight){ 
          //divHeight=divToMatch.style.pixelHeight; 
    //    } 
		
		//divToSet.style.height= divHeight; 


//window.onload=getHeight;