JQuery UI -Dialogposition feste Mitte

$('selector').dialog({
    autoOpen: false,
    open: function(event, ui) {
        $(event.target).dialog('widget')
            .css({ position: 'fixed' })
            .position({ my: 'center', at: 'center', of: window });
    },
    resizable: false
});
Depressed Dolphin