function pop(strUrl,strName,w,h,s) 
	{
	var pop = null;
	strLeft = (screen.width) ? (screen.width-w) /2:0;
	strTop = (screen.height) ? (screen.height-h) /2:0;
	strSett = 'width='+w+',height='+h+',top='+strTop+',left='+strLeft+',scrollbars='+s+',status=no';
		pop = window.open(strUrl,strName,strSett);
		pop.focus();
	}

	function formCheck(formobj){
		var alertMsg = "Vul a.u.b. de volgende verplichte velden in:           \n\n";
		
		var l_Msg = alertMsg.length;
		
		for (var i = 0; i < fieldRequired.length; i++){
			var obj = formobj.elements[fieldRequired[i]];
			if (obj){
				switch(obj.type){
				case "select-one":
					if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == ""){
						alertMsg += " - " + fieldRequired[i] + "\n";
					}
					break;
				case "select-multiple":
					if (obj.selectedIndex == -1){
						alertMsg += " - " + fieldRequired[i] + "\n";
					}
					break;
				case "text":
				case "textarea":
				case "password":
					if (obj.value == "" || obj.value == null){
						alertMsg += " - " + fieldRequired[i] + "\n";
					}
					break;
				default:
				}
				if (obj.type == undefined){
					var blnchecked = false;
					for (var j = 0; j < obj.length; j++){
						if (obj[j].checked){
							blnchecked = true;
						}
					}
					if (!blnchecked){
						alertMsg += " - " + fieldRequired[i] + "\n";
					}
				}
			}
		}
	
		if (alertMsg.length == l_Msg){
			return true;
		}else{
			alert(alertMsg);
			return false;
		}
	}