var ajaxLoader = "<IMG src=\"styles/ajax-loader.gif\" /> ";

function createXHR()
{
  var xhr; 
  try {  xhr = new ActiveXObject('Msxml2.XMLHTTP');   }
  catch (e)
  {
    try {   xhr = new ActiveXObject('Microsoft.XMLHTTP');    }
    catch (e2) 
    {
      try {  xhr = new XMLHttpRequest();     }
      catch (e3) {  xhr = false;   }
    }
  }
     
  return xhr;
}

function calculPoids(){
	var xhr=createXHR();
		//var article = document.getElementById('produit').options[selectedIndex].value;
		var article = document.getElementById('produit').options[document.getElementById('produit').selectedIndex].value 
		var qtite = document.getElementById('qtite').value;
		var dept = document.getElementById('dept').options[document.getElementById('dept').selectedIndex].value 
	var data = "article="+article+"&qtite="+qtite+"&dept="+dept;
	if (xhr)
  {    
    xhr.onreadystatechange  = function()
    { 
         if(xhr.readyState  == 4)
         {
              if(xhr.status  == 200)
				{
					var result = xhr.responseText;
					document.getElementById("resultatpoids").innerHTML=result;
				}
				else document.getElementById("resultatpoids").innerHTML="Error code " + xhr.status;
         }
    };
    document.getElementById("resultatpoids").innerHTML=ajaxLoader+"Calcul en cours...";
    xhr.open("post", "calculpoids.php?", true);
	xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
    xhr.send(data);  
  }
}