var xmlHttp
var id

function addToCart(frm) {

xmlHttp=GetXmlHttpObject()
if (xmlHttp==null)
 {
 alert ("Browser does not support HTTP Request")
 return
 }
var url="add_item.php"
url = url + "?item=" + encodeURI( frm.item.value )
url = url + "&promo=" + encodeURI( frm.promo.value )
url = url + "&item_name=" + encodeURI( frm.item_name.value )
url = url + "&price=" +  encodeURI( frm.price.value )
url = url + "&currency=" +  encodeURI( frm.currency.value )
url = url + "&unit=" +  encodeURI( frm.unit.value )
url = url + "&qty=" +  encodeURI( frm.qty.value )
frm.qty.value = ""
id = 'qty' + frm.item.value
xmlHttp.onreadystatechange=stateChanged
xmlHttp.open("GET",url,true)
xmlHttp.send(null)
}
function stateChanged() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
 { 
 document.getElementById(id).innerHTML = xmlHttp.responseText + ' of this item in your cart' 
 } 
}
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;
}