var ajax = new Array();

function selecteerThema(waarde) {
	var huidigVeld = waarde.options[waarde.selectedIndex].value;

	document.getElementById("selectThema").options.length = 0;
	
	if(huidigVeld.length>0){
		var index = ajax.length;
		ajax[index] = new sack();
		ajax[index].requestFile = '/ajax/select_thema.php?huidigVeld='+huidigVeld;
		ajax[index].onCompletion = function(){ vulSelectThema(index) };
		ajax[index].runAJAX();
	}
}

function vulSelectThema(index) {
	var obj = document.getElementById("selectThema");
	eval(ajax[index].response);
}