One more thing:
Don't ever pass references through a FOR loop by just wiring them in and back out again. In your case you will be wanting to open the file outside the loop, write to it several times inside the loop, and then close it when the loop terminates.
The problem is that (unlike a WHILE loop) a FOR loop can execute zero times. When that happens any datavalues coming from the loop are set to their default state--which in the case of a refnum is an invalid reference.
When passing a refnum through a loop like this always use a shift register. With a shift register, if the loop executes zero times the right terminal will default to the value of the left terminal--which is your valid refnum. (BTW: the same
thing goes for the error clusters on the file IO routines).
Mike...
