Jquery: Running AJAX locally without a webserver

I have the following function in a .js file in index.html

function getValues(){

 $.ajax({
   type: 'POST',
   url: "http://localhost/getData/getdata.php",
   success: function(data){
     var dataValues;
     var apnd;

     dataValues = String(data.NSE);
     apnd = "a";
     updateValues(dataValues, apnd);

     dataValues = String(data.BSE);
     apnd = "b";
     updateValues(dataValues, apnd);
    },
   dataType: "json"
 });

}

this works fine when I run it in a webserver like wamp. But I want to run index.html locally i.e without a webserver, The user just double clicks index.html and it should run but it doesn't. data is always null. What could be the problem? Sorry I am a super JQuery Noob.

the code in getdata.php file is

<?

echo json_encode(array("NSE"=>rand(5000, 20000),"BSE"=>rand(5000, 20000))); 

?>