parameter variables question

[Alex Rice]

Consider a handler that sums it's parameters before doing it's work, 
like this:

on testIt p1, p2
   if p1 + p2 = 0 then
     return "bad parameters"
   else
     -- do stuff
     return empty
   end if
end testIt

Why does this handler throw an error when called like this?

testIt 1, tSomeNonexistentVariable
-- 
-- Message execution error:
-- Error description: Operators +: error in right operand

if (p1 + p2) = 0 does not work either.

Thanks,

Alex Rice, Software Developer
Architectural Research Consultants, Inc.
http://ARCplanning.com