Stupidest question of the day

Stupidest question of the day

Okay, so I've use JQuery before and it's super easy.  For some reason I'm having a mentally challenged moment here.  Help!

I've got the simplest (for test purposes) function imaginable:

$( document ).ready(function() {
$.ajax({
        'type' : 'GET',
        'success' : function(data) {              
            alert('Data: '+data);
        },
        'error' : function(request,error)
        {
            alert("Request: "+JSON.stringify(request));
        }
    });         
});

returns a simple number (you can try it in a browser).  Why the @#$^ does it fall through to the error routine?
Thanks in advance (knowing I'm going to be embarrassed when the answer is shown to me).
-- John