function getQueryVariable(variable) 
{
  var query = window.location.search.substring(1);
  var vars = query.split("&");
  for (var i=0;i<vars.length;i++) {
    var pair = vars[i].split("=");
    if (pair[0] == variable) {
      return pair[1];
    }
  }
  
  return null;
}

function GetXmlHttpObject()
{
    var objXmlHttp = null;

    if(window.XMLHttpRequest)
    {
        objXmlHttp = new XMLHttpRequest();
    }
    else if(window.ActiveXObject)
    {
        try
        {
            objXmlHttp = new ActiveXObject('Msxml2.XMLHTTP');
        }
        catch(e)
        {
            objXmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
        }
    }
    return objXmlHttp;
}

function XmlHttpGet(xmlhttp, url)
{
    xmlhttp.open('GET', url, true);
    xmlhttp.send(null);
}