Global routine name main ambiguous.

sud213 State College
hi all,

i save a very simple code to run on IRB2400/16 Kg with S4C controller. It has one module and ONLY one MAIN Proc but it keep showing that "Global routine  name main ambiguous." on the teach pendent .

What should I do? 
Should I synchronize it to virtual controller or station first? or it is not related. the simulation works perfectly.

Thanks for your answers in advanced!