the confusing thing for me is why sometimes I get the error and sometimes I dont'..

I can start up Foxpro, open the command window and run:

? isnull(x)

which gives me an error because I haven't defined x.

i also know that 'x' has a vartype of 'U' at this point...

but when I'm running the .exe, and I get to the point where the variable in question is referenced, I can see that it also has a vartype of 'U' but the isnull() command that is called on it does *not* error..

that is really my main question is why I would get the error in the command window but not in the .exe in seemingly identical situations..