var xmlhttp = null;
function xmlhttpHandler(url) { 
// code for Mozilla, etc.
   if (window.XMLHttpRequest != null) {
      xmlhttp=new XMLHttpRequest();
      if(xmlhttp.overrideMimeType){
          xmlhttp.overrideMimeType('text/xml');
      }
      xmlhttp.onreadystatechange = function() {
         // if xmlhttp shows "loaded"
         if (xmlhttp.readyState==4) {
         // if "OK"
            if (xmlhttp.status==200) {
               xmlhttpResponse(xmlhttp.responseXML);
            }
            else {
               alert("Problem retrieving XML data");
            }
         }
      }
      var b = url.split("?");
      xmlhttp.open("POST",b[0],true);
      if (b.length > 1 ) {
         //Send the proper header information along with the request
         xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
         xmlhttp.setRequestHeader("Content-Length", b[1].length);
         //xmlhttp.setRequestHeader("Connection", "close");
         xmlhttp.send(b[1]);
      } else {
         xmlhttp.send(null);
      }
   }
   // code for IE
   else
      if (window.ActiveXObject) {
         xmlhttp= new ActiveXObject("Microsoft.XMLHTTP");
         if (xmlhttp) {
            xmlhttp.onreadystatechange = function() {
            // if xmlhttp shows "loaded"
            if (xmlhttp.readyState==4) {
               // if "OK"
               if (xmlhttp.status==200) {
                  xmlhttpResponse(xmlhttp.responseXML);
               }
               else {
                  alert("Problem retrieving XML data");
               }
            }
         }
         xmlhttp.open("POST",url,true);
         xmlhttp.send();
      }
      else {
         alert("Browser doesn't support XMLHTTP protocol");
      }
   }
}
function getFormNum (formName) {
   var formNum =-1;
   for (i=0;i<document.forms.length;i++){
 	    tempForm = document.forms[i];
      if (formName == tempForm) {
         formNum = i;
         break;
      }
   }
   return formNum;
}

function relate(formName,j) {
   var url = '';
   try {
      var formNum = getFormNum(formName);
      var selectNum;
      if (formNum>=0) {
         merk = document.forms[formNum].f_merk.options[j].value;
         url = '/owa_dima/owa/modellen_partner.xml?p_merk=' + merk + '&p_code=MSN';
         xmlhttpHandler(url);
      }
   } catch (e) {
      if (e instanceof TypeError) {
      //vang type errors op
      }
   }
}
function xmlhttpResponse(dom) {
   try {
      var poplist       = document.occasion.f_model;
      var pmodel        = document.occasion.p_model;
      var poplist_value = dom.getElementsByTagName('MODEL');
      with (poplist) {
         for(i=options.length-1;i>0;i--)
         {
            options[i] = null;
         }
         // altijd een default option
         options[0] = new Option('alle modellen','');
         // vul de poplist
         for (var i=0; i<poplist_value.length;i++) 
         {
            options[i+1] = new Option(poplist_value[i].firstChild.nodeValue,poplist_value[i].firstChild.nodeValue);
            if ((poplist_value[i].firstChild.nodeValue == pmodel.value) && (pmodel.value != null)) 
               options[i+1].selected = true; 
            else options[i+1].selected = false 
         }
      }
   } catch (e) {
      if (e instanceof TypeError) {
      //vang type errors op
      }
   }
}