function showadiv(el_id, tekst){
	var el=document.getElementById(el_id);
	if(el_id.style.display!=""){
		el_id.style.display="";
	} else {
		el_id.style.display="block";
	}
	el.innerHTML = tekst;
}


function checkform(form) {
	var radioval = 0;
	var hasRadio = 0;
	for (var x=0; form.elements[x]; x++ ) {
		if (form.elements[x].type == 'radio') {
			var radios = document.getElementsByName(form.elements[x].name);
			for (var i = 0;i<radios.length;i++){
				hasRadio++;
				radioval += radios[i].checked+ 0;
			}
       if ((hasRadio) && (radioval== 0)) {
	         alert("Kies een van de opties (radio buttons)" );
					return false;
				}
		} else {
    	if (form.elements[x].value == 0){
	      if(form.elements[x].id != "nocheck") {
        	alert( "Vergeten het '" + form.elements[x].id + "' veld in te vullen?" );
          form.elements[x].focus();
          return false ;
        }
      }
    }
	}
}