JQuery issue with no response from server (localhost) with different browsers

I have what is a simple script to retrieve a simple message (string) from server and it appears there is no response from server, so I am wondering if JQuery is even firing off a request at all?

The server side script (PHP) is so simple, basically it is just a plain echo. One moment the script is working in FF and the next moment it ain't, as for the other mainstream browsers, you can forget about it!

Here is the JQuery script below, do you see anything I'm missing (considering I am new to JQuery / AJAX / Still learning)? Thanks.

$(document).ready( function() {

            $( '.enlarge' ).click(function( e ) {

                e.preventDefault(); 



                var img = $( this ).children( 'img' ).attr( 'alt' );

                var url = '/pages/message/' + img + '/';



                $.ajax({

                    url: url,

                    data: '',

                    cache: false,

                    dataType: 'text',

                    beforeSend: function( rs ) {

                        $( '#gallery-message' ).html( '<p class="para"><img src="/media/images/spinner.gif" />Please wait...</p>' );  

                    },

                    success: function( rs ) {

                        $( '#gallery-message' ).html( rs );

                        $( '#gallery-window' ).children( 'p' ).children( 'img' ).attr( 'src', '/media/images/pages/gallery/' + img + '.jpg' );

                    },

                    error: function( rs, err ) { 

                        if( rs.status == 0 ) {

                            alert( '--- Offline' );

                        } else if( rs.status == 404 ) {

                            alert( '404 Not Found' );

                        } else if( rs.status == 501 ) {

                            alert( '501 Internal Error' );

                        } else if( err == 'timeout' ) {

                            alert( '--- Timeout' );

                        } else {

                            alert( '--- Unknown' );

                        }                       

                    }



                });



            });

        });

What is happening is that I get an alert "--- Offline" as per the check on there being an error or not. The HTML I can post if you wish but there is nothing taxing about that either, simply a message is sent from server which replaces an existing message based on which thumbnail image was clicked.