IDL 5.6, Marc; I think it's time to upgrade, don't you?

Anyhow, I am not sure what scenario you are describing. I particularly do not understand why you would have an undefined function in an IDL_STARTUP batch program. If it is causing a problem, why not remove the call to it from your startup file? ... or why not get rid of a '.pro' version of it, which is corrupt, and replace it with a properly functioning version? I must be misunderstanding your scenario.

In any case, the command to change directories is 'CD', and you can add that to your startup script (or to your "corrupted .pro", e.g.:

CD, 'C:\Documents and Settings\mgilgen\idl_source_code'

Now that I wirte this, I am starting to think that the problem with your "corrupt .pro" is that it is corrupt only because its "relative paths" are breaking since your startup files changed. If this is indeed the problem, see ITT Visual Information Solutions Tech Tip #4102 ("A Smart Way To Help IDL Find Data Files In Your File System")

James Jones
ITT Technical Support