function getURLParameter(sName) 
{
  var sURL = window.document.URL.toString();
  if (sURL.indexOf("?") > 0){
    var arrParams = sURL.split("?");
    var arrURLParams = arrParams[1].split("&");
    var i = 0;
    for (i=0;i<arrURLParams.length;i++) {
      var sParam = arrURLParams[i].split("=");
      if (sName == sParam[0]) return unescape(sParam[1]);
    }
    return null;
  } else {
    return null;
  }
}