Timed Dialog

I'm trying to have a Dialog box with a countdown timer of how long the person has to choose an option before going to a default value. I was wondering how this could be accomplished because when I try and display a dialog, the game pauses. So let's say after 20 seconds the person hasn't selected an option, I want the dialog to disappear and automatically select a default value. I'm sure it can be done because I believe I've seen it somewhere before.

When you play your map in singelplayer (custom game) it will pause every time a dialog appears.

However, if you host it in a private multiplayer game with only yourself, it won't pause.

Damn, I feel stupid. Thanks!