[jquery] Passing multiple parameters with $.ajax url

I am facing problem in passing parrameters with ajax url.I think error is in parametters code syntax.Plz help.

    var timestamp = null;
function waitformsg(id,name) {

    $.ajax({
        type:"Post",
        url:"getdata.php?timestamp="+timestamp+"uid="+id+"uname="+name,
       async:true,
       cache:false,
       success:function(data) {


        });
     }

I am accessing these parameters as follows

<?php          

  $uid =$_GET['uid'];


 ?>

why not just pass an data an object with your key/value pairs then you don't have to worry about encoding

$.ajax({
    type: "Post",
    url: "getdata.php",
    data:{
       timestamp: timestamp,
       uid: id,
       uname: name
    },
    async: true,
    cache: false,
    success: function(data) {


    };
}?);?