Debugging existing FOX formula

Hi Experts,

I am Anil new to BPS.

can any one help me in debugging existning FOX FORMULA.

I have FOX CODE, which i need to debug and need to know what values are getting in each condition.

1. I am not able to get the code in to change mode.

2. How can i use the BREAKPOINT to know the status till one point.

Thanks in Advance,

Anil.