need help in expression
 

Please if any one can help ?
while i;am working in expression i encountered this message:

Warning: Cycle on 'particleShape1.output[1]' may not evaluate as expected. (Use 'cycleCheck -e off' to disable this warning.)
i d'nt known from where to turn (cycleCheck -e) off

your answer will be highly appreciated.

its just a warning. not an error, so no worries.
it tells you how to turn off the warning.

If you type in cycleCheck -e off into the MEL line at the bottom of your screen (if it says Python just click Python to toggle to MEL) it will no longer give you this warning.
What it means is this: Particles feed information to itself cyclically based on time, (e.g. their previous position at the frame before plus new information gives new position) so if you move backwards in the timeline, or if you jump to the first frame 1, you're screwing up this cyclical flow of information (nothing to worry about) and it's just warning you that it might not give you expected behaviour. That's my understanding based on what I think I remember learning. Hope that makes some sense.