var xmlHttp

function sortby(str,keywords) //str is the sort by id
{ 
xmlHttp=GetXmlHttpObject();
if (xmlHttp==null)
  {
  alert ("Your browser does not support AJAX!");
  return;
  }
var qrystr=parent.document.URL;
i=qrystr.indexOf("key_id=")+7; //locate the position of key_id value
j=qrystr.indexOf("&g_id="); //locate the position of g_id value
key_id=qrystr.substring(i,j); //get the key_id value
g_id=qrystr.substring(j+6); //get the g_id value
var url="../Ajax/GetItemlist.aspx"; //ASP page to retrieve data from SQL database
url=url+"?key_id="+key_id; //primary key id - filter primary key, 0 - no filter
url=url+"&g_id="+g_id; //global id - 0-search, 1-vendor, 2-category, 3-all, 4-wanted, 5-all
url=url+"&s_id="+str; //sort by id - 1-new, 2-today, 3-soon, 4-new, 5-all
url=url+"&keywords="+keywords; //search keywords
xmlHttp.onreadystatechange=stateChanged;
xmlHttp.open("GET",url,true);
xmlHttp.send(null);
}

function stateChanged() 
{ 
if (xmlHttp.readyState==4)
{ 
document.getElementById("itemlist").innerHTML=xmlHttp.responseText; //send HTML text to itemlist object
}
}

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;
}