Using jquery's $.ajax function, I'm not able to parse the results. For example, I used it like this

```
$.ajax({

    url : "http://api.twitter.com/1/users/show.json?screen_name=techcrunch",
    dataType : "json",
    success : function(data)
    {
        // parse the JSON here
    },
    error : function()
    {
        alert("Failure!");
    },

});

```

This doesn't work. Do I need a callback function?