jQuery(jsonp) + PHP

javascript code

$.ajax({
   url: "http://example.com/load_data.php",
   dataType: "jsonp",
   jsonpCallback: 'jsonCallback',
   success: function(data){
      alert("success");
   },
   error:function(){
      alert("failure");
   }
});

PHP code

header("Content-Type: application/json");
require_once "connect_db.php";
$sql = "select * from Table";

 $res = mysql_query($sql) or die(mysql_error());
 $data = array();
 while($row = mysql_fetch_array($res)){
  array_push($data,$row);
 }
 echo $_GET['callback'].'('.json_encode($data).')';