asp.net - Check Integer Value on Asmx -

i have sample web method on services,

 <webmethod()> _ public function addthis(byval x integer, byval y integer) integer      dim mysum integer      if not isnumeric(x)         return 0     end if     mysum = x + y     return mysum  end function 

when debug it, suddnely made mistake x or y value , , give me error :

system.argumentexception: cannot convert gf system.int32. parameter name: type ---> system.formatexception: input string not in correct format.

i try check value :

if not isnumeric(x)             return 0         end if 

but keep getting error, possible check value first before run services?

at point check "isnumeric(x)", x numeric. expect integer parameters, error occur moment call function addthis.

you have check x , y before calling function. or if not possible, use this:

public function addthis(byval x string, byval y string) integer      dim mysum integer      if not isnumeric(x) or not isnumeric(y)         return 0     end if     mysum = integer.parse(x) + integer.parse(y)     return mysum  end function