var http = null;
var send = null;

function makeRequest(url){
   var makeRequest = true;
   
   if(document.getElementById("primary") != null){
      if(document.getElementById("primary").checked == true){
         document.getElementById("dealer_options").disabled = false;
      }else{
         document.getElementById("dealer_options").disabled = true;
         makeRequest = false;
      }
   }

   if(makeRequest == true){
      if(window.XMLHttpRequest){
         http = new XMLHttpRequest();
      }else if(window.ActiveXObject){
         http = new ActiveXObject("Microsoft.XMLHTTP");
      }
      if(http != null){
         //http.open("GET", "dealers.php", true);
         //http.onreadystatechange = outputDealers;
         //http.send(null);

         http.onreadystatechange = outputDealers;
         http.open('POST', url, true);
         http.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
         if(document.getElementById('postcode').value != ''){
            send = 'postcode=' + document.getElementById('postcode').value;
         }
         http.send(send);
      }
   }
}

function outputDealers(){
   if(http.readyState == 4){
      var data = http.responseText;
      data = eval("(" + data + ")");

      document.getElementById("dealer_options").options.length = 0;
      var list = document.getElementById("dealer_options");
      for(var i=0; i<data.length; i++){
          var dealer = data[i];
          var option = document.createElement("option");
          option.setAttribute("value", dealer.customers_id);
          var txt = document.createTextNode(dealer.entry_company);
          option.appendChild(txt);
          list.appendChild(option);
      }
   }
}