Class,

Don't ask me to regrade assignments Jon has already graded unless you are sure your assignment, as posted on CSNS, actually works. You are not allowed to modify your assignment and demo it to me on your computer: that's cheating. You have to submit your work on CSNS by the due date and time, just like everyone else. 

If you ask for a regrade and I do it and get the same error that Jon got, or if there is a clear mistake in your code/assignment that warrants Jon's grade, I will deduct 3 points from your assignment for wasting my time.

Bottom line: Only ask for a regrade if you are really sure the grader made a mistake.