<!-- Begin

function checkradio(wich)
  {
  var radio_choice = false;
  
  var radioname = wich.name; 
  var theform = wich.form; 
  var theradiocollection = theform[radioname];
  
  for (counter = 0; counter < theradiocollection.length; counter++)
    {
    if (theradiocollection[counter].checked)
      {
      radio_choice = true; 
      }
    }
  return radio_choice;
  }


function checkrequired(which)
  {
  var pass=true;

  if (document.images)
    {
    for (i=0;i<which.length;i++)
      {
      var tempobj=which.elements[i];

      var isRequired = tempobj.required;

      if (isRequired==undefined)
        {
        isRequired=tempobj.getAttribute('required');
        }

      if (isRequired!=null)
        {
        if (
           ((tempobj.type=="text"||tempobj.type=="password"||tempobj.type=="textarea")&&tempobj.value=='')
           ||
           (tempobj.type.toString().charAt(0)=="s"&&tempobj.selectedIndex==0)
           ||
           (tempobj.type=="radio"&&checkradio(tempobj)==false)
           )
          {
          tempobj.style.backgroundColor='red';
          pass=false;
          break;
          }
        else
          {
          tempobj.style.backgroundColor='';
          }
        }
      }
    }

  if (!pass)
    {
    shortFieldName=tempobj.name;
    alert("Er is een fout opgetreden:\n\n\""+shortFieldName+"\" is verplicht");
    tempobj.focus();
    return false;
    }
  else
    {
    return true;
    }
  }
//  End -->