[DIALOG]Overlay not sized properly

[DIALOG]Overlay not sized properly


Firstly, I would like to apologize if this has been asked, I have been
searching for an answer to this all day.
I am using a dialog to display a loading message between ajax content
loads. Using the overlay, it is always being set to exactly 485PX,
taking up only 1/3 of my page. I have viewed countless examples of the
overlay working correctly, but have failed to get it to work myself.
I have tested this on firefox3 and IE7 with the same results.
My code:
            $('#loaderContainer').dialog({
                autoOpen: false,
                title: 'Loading, Please wait...',
                modal: true,
                overlay: {
                    opacity: 0.5,
                    background: 'black',
                },
                height: 100,
                width: 156,
                draggable: false,
                resizable: false,
            });
I would greatly appreciate some help.
Thank you,
Mike Conway