var xmlHttp

function change_model(str,form)
{ 
	var i;
	var loc = document.getElementById("ap_model");
	if (loc != null)	
	 for (i = form.ap_model.options.length; i > 0; i--)
		 form.ap_model.options[i] = null;

	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	 {
	 alert ("Browser does not support HTTP Request")
	 return
	 }

var url="get_modele.php"	 
	url=url+"?idm="+str
	url=url+"&sid="+Math.random()
	xmlHttp.onreadystatechange = catChanged
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
}



function catChanged() 
{ 
 if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
  { 
	document.getElementById("div_modele").innerHTML=xmlHttp.responseText
 } 
}


function GetXmlHttpObject()
{
var xmlHttp=null;
try
 {
 // Firefox, Opera 8.0+, Safari
 xmlHttp=new XMLHttpRequest();
 }
catch (e)
 {
 //Internet Explorer
 try
  {
  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  }
 catch (e)
  {
  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
return xmlHttp;
}