Changing records in one field based on another

[kerwinhack]

I am trying to update a field based on the value in another but get this error message: Error: Formula (66): Parse Error at char(76): Parse Error (Expression #3)

This is the formula I am using:

Any suggestions?

[kerwinhack]

Thanks, it looks like it was the field type that was causing the problem, changing it to String and making sure the character count was high enough solved the problem.