jQuery UI dialog box not positioned center screen

Question

I have a jQuery dialog box that is meant to position in the middle of the screen. However, it seems slightly off-center vertically.

Here is the code:

Answer 1

Digging up an old grave here but for new Google searchers.

You can maintain the position of the model window when the users scrolls by adding this event to your dialog. This will change it from absolutely positioned to fixed. No need to monitor scrolling events.

open: function(event, ui) {
    $(this).parent().css('position', 'fixed');
}