Ajax request not working in IE

I have an Ajax code inside my Php and it works smoothly in Chrome but not in IE

HELP HELP HELP !!!!

code is ;

function ajaxRequest(){

var activexmodes=["Msxml2.XMLHTTP", "Microsoft.XMLHTTP"] //activeX versions to check for in IE

if (window.ActiveXObject){ //Test for support for ActiveXObject in IE first (as XMLHttpRequest in IE7 is broken)

  for (var i=0; i<activexmodes.length; i++){

  try{

    return new ActiveXObject(activexmodes)

  }

  catch(e){

    //suppress error

  }

  }

}

else if (window.XMLHttpRequest) // if Mozilla, Safari etc

  return new XMLHttpRequest()

else

  return false

}

function getajax() {

var mypostrequest=new ajaxRequest()

mypostrequest.onreadystatechange=function(){

if (mypostrequest.readyState==4){

  if (mypostrequest.status==200 || window.location.href.indexOf("http")==-1){

  document.getElementById("content").innerHTML=mypostrequest.responseText

  }

  else{

  alert("An error has occured making the request")

  }

}

}

var pinval = encodeURIComponent(document.getElementById("pin").value)

var fval = encodeURIComponent(document.getElementById("func").value)

var parameters="cid="+pinval+"&f="+fval

mypostrequest.open("POST", "forecast.inc.php", true)

mypostrequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded")

mypostrequest.send(parameters)

}