How to attach callback to jquery effect on dialog show?

My problem is that I do not know how to attach callback to the jquery ui dialog show.

The show is actually an option:

$( ".selector" ).dialog({ show: 'slide' });

I want to have a callback after the slide animation is complete. I looked from the effects itself and they have a callback:

effect( effect, [options], [speed], [callback] )

But in the dialog the effect is set up very differently. I tried also putting:

$( ".selector" ).dialog({ show: 'slide', callback: function() {} });

But it didn't work.

Suggestions?