GetParamValue heartbeat

var timer;
var usingERIS=true;
var _xmlHttp=null;
 
function GetParamValue(name)
{
  var reg = new RegExp("(^|\\?|&)"+ name +"=([^&]*)(\\s|&|$)", "i"); 
  if (reg.test(window.location.href))
  {
      return RegExp.$2;
  } 
  return "";
}
   
// Create XMLHttpRequest object
function getXMLHTTP() {
 var xmlHttpObject=null;

 try {
  xmlHttpObject=new ActiveXObject("Msxml2.XMLHTTP");
 } catch (e) {
  try {
   xmlHttpObject=new ActiveXObject("Microsoft.XMLHTTP");
  } catch (oc) {
   xmlHttpObject=null;
  }
 }
 if ((!xmlHttpObject)&&(typeof(XMLHttpRequest!="undefined")))
  xmlHttpObject=new XMLHttpRequest();
 return(xmlHttpObject);
}

// Send a http request
function sendHttpRequest() {
 if (_xmlHttp) {
  _xmlHttp.open("GET", url, true);
  _xmlHttp.onreadystatechange=OnReady;
  _xmlHttp.send(null);
 }
}

function OnReady(){
   if ((_xmlHttp.readyState==4)&&(_xmlHttp.responseText)) {
    if (_xmlHttp.responseText.indexOf("FAIL")==0) {
     alert("The record is already locked by another user");
     window.location.href='/Web/Navigation/Welcome.aspx';     
    }
    else
     window.setTimeout("sendHeartbeat()", heartbeat_period);
   }
  }

// Send heartbeat by XMLHttpRequest object
function sendHeartbeat() {
 //if (enable_lock=='Y') {
  if ((_xmlHttp)&&(_xmlHttp.readyState!=0))
   _xmlHttp.abort();
  _xmlHttp=getXMLHTTP();
  if (usingERIS==true)
   sendHttpRequest();
 //}
}

// Prompt if the user is idle for too long
function promptAlive() {
 var message = 'Your data entry session has been idled too long, would you like to continue?';
 window.focus();
 usingERIS=false;
 
 usingERIS = confirm(message);
 if (usingERIS==true) {
  sendHttpRequest();
  window.setTimeout("sendHeartbeat()", heartbeat_period);
  resetIdleTimer();
 }
 else
 {  
     window.location.href='./Navigation/Welcome.aspx';
 }
}

// Reset the timer for user idle
function resetIdleTimer() {
 //if (enable_lock=='Y') {
  if (timer)
   window.clearInterval(timer);
  timer=window.setTimeout("promptAlive()", max_idle_time);
 //}
}