jQuery .get error response function?

You can chain .fail() callback for error response.

$.get('http://example.com/page/2/', function(data){ 
   $(data).find('#reviews .card').appendTo('#reviews');
})
.fail(function() {
  //Error logic
})

You can get detail error by using responseText property.

$.ajaxSetup({
error: function(xhr, status, error) {
alert("An AJAX error occured: " + status + "\nError: " + error + "\nError detail: " + xhr.responseText);
     } 
    });

If you want a generic error you can setup all $.ajax() (which $.get() uses underneath) requests jQuery makes to display an error using $.ajaxSetup(), for example:

$.ajaxSetup({
  error: function(xhr, status, error) {
    alert("An AJAX error occured: " + status + "\nError: " + error);
  }
});

Just run this once before making any AJAX calls (no changes to your current code, just stick this before somewhere). This sets the error option to default to the handler/function above, if you made a full $.ajax() call and specified the error handler then what you had would override the above.

$.get does not give you the opportunity to set an error handler. You will need to use the low-level $.ajax function instead:

$.ajax({
    url: 'http://example.com/page/2/',
    type: 'GET',
    success: function(data){ 
        $(data).find('#reviews .card').appendTo('#reviews');
    },
    error: function(data) {
        alert('woops!'); //or whatever
    }
});

---

Edit March '10

Note that with the new jqXHR object in jQuery 1.5, you can set an error handler after calling $.get:

$.get('http://example.com/page/2/', function(data){ 
    $(data).find('#reviews .card').appendTo('#reviews');
}).fail(function() {
    alert('woops'); // or whatever
});