GNAT response deadline

Hello!
What is the response deadline for the sample GNAT available at the DirectRT site? I couldn't figure out how the timing information (rt:57,-1<-999 or rt:-1,57<-999) codes response deadline. That is, how many seconds after it will jump to the next trial.
I am trying to set the response deadline as 750 msec so that if the participant does not respond within 750 msec, it will move onto the next trial.
How should I do that?
Thanks!

Yoona

oh actually I think I figured it out... the response deadlines can be modified in the styles file, right?