[jQuery] blockUI / jqModal - unload issues

[manwood]

I am trying to use either BlockUI or jqModal to display a modal dialog
when the page unloads but it just won't work (in IE7).

Using jqModal THIS WORKS (attaching to an <a> tag):

$().ready(function() {

    $('#confirm').jqm({ overlay: 88, modal: true, trigger: false });

    $('#navigationBlock a').click(function() {
        confirm('changes have not been saved');
        return false;
    });
});

But THIS DOES NOT WORK (attaching to the unload event):

$().ready(function() {

    $('#confirm').jqm({ overlay: 88, modal: true, trigger: false });

    $(window).unload(function() {
        confirm(''changes have not been saved'');
        return false;
    });
});


Using BlockUI, THIS WORKS:

$(document).ready(function() {

    $('#navigationBlock a').click(function() {
        $.blockUI({ message: $('#question'), css: { width:
'275px'} });
    });
});


But THIS DOES NOT WORK:

$(document).ready(function() {

    $(window).unload(function() {
        $.blockUI({ message: $('#question'), css: { width:
'275px'} });
    });
});

Any advice or suggestions are much appreciated.