Trap Backspace to prevent dialog closing.

gistfile1.js

function portfolioEditorDialogdialogRequestedHandler() {
    $(document).bind('keydown', function (event) {
        if (event.which == 8) {
            var target = $(event.target);
            if (!target.is('input'))
                event.preventDefault();
        }
    });
}

function portfolioEditorDialogdialogUnrequestedHandler() {
    $(document).unbind('keydown');
}