DVD Authoring GUI

Hello.

I am searching for a way to make a default button in a menu.
So when I press the 'go to chapter' button and the dvd switch to the chapters menu it would be great to see button 1 highlighted. Now it's always a surprise which one is highlighted.
I know found that I have to fill in something in the pre command section of a menu but I can't find the right commands.

I hope someone can help,
Jurgen