>In VFP, variables are not predefined. Is there any tools to check all the varibeles or list them. Because if you type a wrong variable you won't know it until user run the program and get error. Thanks a lot.

Mike,

By default any variables declared as PRIVATE or LOCAL are initialized to .F.

What I do is to add the variables to a LOCAL statement as I first access or assign them.

This is really a problem with testing. If you properly test the code, then these issues go away.