var nowactive='';
var old='';
function active(im){
	old = nowactive;
	nowactive = im;
	document[im].src = 'img/btn/' + im + '_s.gif';
}
function flipoff(im){
	if (nowactive!=im){
		document[im].src = 'img/btn/' + im + '.gif';
	}
}
function flipon(im){
	document[im].src = 'img/btn/' + im + '_s.gif';
}

var myimg=new Array();
function preloadimg(){
	for (i=0;i<preloadimg.arguments.length;i++){
		myimg[i]=new Image();
		myimg[i].src=preloadimg.arguments[i];
	}
}
preloadimg("img/btn/en_s.gif", "img/btn/nl_s.gif", "img/btn/es_s.gif", "img/btn/it_s.gif", "img/btn/fr_s.gif");

function checkform(form) {
    for (var x=0; form.elements[x]; x++ ) {
		//alert( form.elements[x] );
		if(form.elements[x].alt == "verplicht") {
        	if (form.elements[x].value == ""){
	        alert( "Please fill in the required field: '" + form.elements[x].id + "'" );
            form.elements[x].focus();
            return false ;
            }
        }
    }        
}
var popupWin = null;

function openWin(target, width, height)
{
	var popupTop = (screen.height - height)/2;
	var popupLeft = (screen.width - width)/2;

	if(popupWin == null || popupWin.closed)	
	{
		popupWin = window.open(target,'houtappels','scrollbars=no,resizable=no,top=' + popupTop + ',left=' + popupLeft + ',status=no,width=' + width + ',height=' + height);
	}
	else
	{
		popupWin.location = target;
		setTimeout("popupWin.focus()",0)
	}
}
if (top != self) {
  parent.top.location = 'index.php';
}

function goto(hs){
	document.toetsForm.hs.value=hs; 
	document.toetsForm.submit();
}