function checkform(fobj){
	if(fobj.elements){
		for(e=0;e<fobj.elements.length;e++){
		  if(fobj.elements[e].getAttribute('req')==1){
		  	if(fobj.elements[e].value==''){
				document.getElementById(fobj.elements[e].name+'_err').innerHTML='dit is een verplicht veld';
				return false;
			}
			else{
				document.getElementById(fobj.elements[e].name+'_err').innerHTML='';
			}
		  }	
		}
	}
	return true;
}

function hidediv(id) {
    obj = document.getElementsByTagName("div");
    obj[id].style.display = 'none';
}

function showdiv(id) {
    obj = document.getElementsByTagName("div");
    obj[id].style.display = 'block';
}

function showhide(id){
  obj = document.getElementsByTagName("div");
  if(obj[id].style.display=='block'){
    hidediv(id);
  }
  else{
    showdiv(id);
  }
}