problem with subracting from number that I get with cgi module

[Jeremy Lunn]

Hi,

I am trying to get a number with the cgi modules like:
form = cgi.FieldStorage()
num = urlargs["num"].value

But I can't subtract from it, when I try to do that like:
newnum = num-1

I get an error like this:
Traceback (innermost last):
  File "./numtest.py", line 9, in ?
    numtwo = num-1
TypeError: bad operand type(s) for -

Would this mean that the number I am getting isn't really a number or
what?

Anyone have any ideas how I could get this to work?

Thanks

Jeremy
      

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Jeremy Lunn
Melbourne, Australia
ICQ: 19255837