function checkrequired(which) { 
var pass=true; 
if (document.images) { 
for (i=0;i<which.length;i++) { 
var tempobj=which.elements[i]; 
if (tempobj.name.substring(0,8)=="required") { 
if (((tempobj.type=="text"||tempobj.type=="textarea")&& 
tempobj.value=='')||(tempobj.type.toString().charAt(0)=="s"&& 
tempobj.selectedIndex==0)) { 
pass=false; 
break; 
         } 
      } 
   } 
} 
if (!pass) { 
shortFieldName=tempobj.name.substring(8,30).toUpperCase(); 
alert("Gelieve "+shortFieldName+" in te vullen aub."); 
return false; 
} 
else 
return true; 
}