function getParameter ( queryString, parameterName ) {
    // Add "=" to the parameter name (i.e. parameterName=value)
    var parameterName = parameterName + "=";
    if ( queryString.length > 0 ) {
        // Find the beginning of the string
        begin = queryString.indexOf ( parameterName );
        // If the parameter name is not found, skip it, otherwise return the value
        if ( begin != -1 ) {
            // Add the length (integer) to the beginning
            begin += parameterName.length;
            // Multiple parameters are separated by the "&" sign
            end = queryString.indexOf ( "&" , begin );
            if ( end == -1 ) {
                end = queryString.length
            }	
            // Return the string
            return unescape ( queryString.substring ( begin, end ) );
        }	
        // Return "null" if no parameter has been found
        return "null";
    }	
}	

function init() {
    var layer = getParameter(window.location.search,'layer');
    if(layer) document.getElementById('sub-menu').getElementsByTagName('a')[layer-1].onclick();
}
function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.0
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && document.getElementById) x=document.getElementById(n); return x;
}

function MM_nbGroup(event, grpName) { //v3.0
  var i,img,nbArr,args=MM_nbGroup.arguments;
  if (event == "init" && args.length > 2) {
    if ((img = MM_findObj(args[2])) != null && !img.MM_init) {
      img.MM_init = true; img.MM_up = args[3]; img.MM_dn = img.src;
      if ((nbArr = document[grpName]) == null) nbArr = document[grpName] = new Array();
      nbArr[nbArr.length] = img;
      for (i=4; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
        if (!img.MM_up) img.MM_up = img.src;
        img.src = img.MM_dn = args[i+1];
        nbArr[nbArr.length] = img;
    } }
  } else if (event == "over") {
    document.MM_nbOver = nbArr = new Array();
    for (i=1; i < args.length-1; i+=3) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = (img.MM_dn && args[i+2]) ? args[i+2] : args[i+1];
      nbArr[nbArr.length] = img;
    }
  } else if (event == "out" ) {
    for (i=0; i < document.MM_nbOver.length; i++) {
      img = document.MM_nbOver[i]; img.src = (img.MM_dn) ? img.MM_dn : img.MM_up; }
  } else if (event == "down") {
    if ((nbArr = document[grpName]) != null)
      for (i=0; i < nbArr.length; i++) { img=nbArr[i]; img.src = img.MM_up; img.MM_dn = 0; }
    document[grpName] = nbArr = new Array();
    for (i=2; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = img.MM_dn = args[i+1];
      nbArr[nbArr.length] = img;
  } }
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}

function MM_showHideLayers() { //v3.0
  var i,p,v,obj,args=MM_showHideLayers.arguments;
  for (i=0; i<(args.length-2); i+=3) if ((obj=MM_findObj(args[i]))!=null) { v=args[i+2];
    if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v='hide')?'hidden':v; }
    obj.visibility=v; }
}


function getWindowHeight() {
var windowHeight=0;
if (typeof(window.innerHeight)=='number') {
windowHeight=window.innerHeight;
}
else {
if (document.documentElement&&
document.documentElement.clientHeight) {
windowHeight=
document.documentElement.clientHeight;
}
else {
if (document.body&&document.body.clientHeight) {
windowHeight=document.body.clientHeight;
}
}
}
return windowHeight;
}

function setDIVHeight() {
if (document.getElementById) {
	var windowHeight=getWindowHeight();
	if (windowHeight>0) {
	var contElement=document.getElementById('container');
	contElement.style.height=windowHeight - 30 + "px";
	var tekstTools=document.getElementById('tekst-tools');
	if (tekstTools) tekstTools.style.height=windowHeight - 240 + "px";
	var tekstElement=document.getElementById('tekst-een');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-twee');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-drie');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-vier');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-vijf');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-zes');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-zeven');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-acht');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-negen');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-tien');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-elf');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-twaalf');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	var tekstElement=document.getElementById('tekst-contact');
	if (tekstElement && !tekstTools) tekstElement.style.height=windowHeight - 260 + "px";
	}
}
}

window.onresize = function(){
	setDIVHeight();
}

function checksubmit()
{
   if (document.vtbform.workshop.checked && document.vtbform.workshop_type.value == "")
   {
      alert("U hebt de naam van de workshop niet ingevuld.")
      document.vtbform.workshop_type.focus()
      return false
   }
   if (document.vtbform.vocaltool.checked && document.vtbform.vocaltool_type.value == "")
   {
      alert("U hebt de naam van de Vocal Tool niet ingevuld.")
      document.vtbform.vocaltool_type.focus()
      return false
   }
   if (document.vtbform.anders.checked && document.vtbform.anders_text.value == "")
   {
      alert("U hebt uw achtergrond niet aangegeven.")
      document.vtbform.anders_text.focus()
      return false
   }
   if (document.vtbform.naam.value == "")
   {
      alert("U hebt uw naam niet ingevuld.")
      document.vtbform.naam.focus()
      return false
   }
   if (document.vtbform.email.value == "")
   {
      alert("U hebt uw emailadres niet ingevuld.")
      document.vtbform.email.focus()
      return false
   }
   if (document.vtbform.telnr.value == "")
   {
      alert("U hebt uw telefoonnummer niet ingevuld.")
      document.vtbform.telnr.focus()
      return false
   }
/* Albert:: voorlopig weggehaald wegens problemen
	var myindex=document.vtbform.naar.selectedIndex;
	if (myindex==0) {
		alert("U hebt niet aangegeven naar wie het formulier moet worden verzonden.");
		document.vtbform.naar.focus();
	    return false
	}
*/
   return true
}