webapp unique id for analytics

unique_id.js

function adbotGetCookie(c_name) {
  var i,x,y,ARRcookies=document.cookie.split(";");
  for (i=0;i<ARRcookies.length;i++)
  {
    x=ARRcookies[i].substr(0,ARRcookies[i].indexOf("="));
    y=ARRcookies[i].substr(ARRcookies[i].indexOf("=")+1);
    x=x.replace(/^\s+|\s+$/g,"");
    if (x==c_name){return unescape(y);}
  }
}

function adbotSetCookie(c_name,value,exdays)
{
  var exdate=new Date();
  exdate.setDate(exdate.getDate() + exdays);
  var c_value=escape(value) + ((exdays==null) ? "" : "; expires="+exdate.toUTCString());
  document.cookie=c_name + "=" + c_value;
}

function guidGenerator() {
    var S4 = function() {
       return (((1+Math.random())*0x10000)|0).toString(16).substring(1);
    };
    return (S4()+S4()+"-"+S4()+"-"+S4()+"-"+S4()+"-"+S4()+S4()+S4());
}

function adbotGetSessionId()
{
  var sid=adbotGetCookie("__adbot_sid");
  if (sid!=null && sid!="") {
    return sid;
  }
  else {
    sid = new Date().getTime().toString()+"."+guidGenerator();
    adbotSetCookie("__adbot_sid",sid,365);
    return sid;
  }
}