$.getJSON

FireBug ScreenShot

FireBug Screen Shot

Problem
But I did not get the alert though I have used the following code

Javascript used in this page

    <script type="text/javascript">
        $(document).ready(function() {
            var url = "ticker.js?callback=?";
            $.getJSON(url, function(data) {
                alert(data.price);
            });
      
        });
    </script>    

And remote file ticker.js file only contains
    {"ticket":"IBM","price":14.57} 

But
Without using "callback?" it works in Firefox and IE. I did not try it in any other browser. If you would like to see the demo you can visit here callback? ..X