I am trying to write a program but am having difficulty with the syntax function

Code:
program define roccut, rclass
    version 13
    syntax varlist(max=2) [if] [in] [,GSCutoff(integer 10)]
This program is supposed to take in 2 variables (a gold standard and a new measure) and determine and ideal cut off point.

When I try to feed in:
Code:
roccut score1 score2, GSC(15)
I get the error "option GSC() not allowed"

Is there something I am doing wrong? The program works without options.

Thanks