How to determine if the button is pressed or not in L4 Dope?

[Lynette Lin]

Hi all,

I am trying to write an application in L4 Dope. 
Right now, I face a problem. I need to determine if the button is pressed by user or not. 
In the dope-users-guide.txt, there is a function: dope_req() . I tried to use it to check the button event, but failed.
Is anyone know the way to figure it out? Thanks a lot.

Best Regards,
Lynette