[Zope] lower(), how?

I saw this in your http://www.zope.org/Documentation/Articles/ZODB1 choice=raw_input("Press 'L' to list employees, 'A' to add" "an employee, or 'Q' to quit:") choice=choice.lower() I can't get that lower() thing to work. I tried for example: n = raw_input("Guess a number between 1 and 100") n.lower() but I just get AttributeError: 'string' object has no attribute 'lower'