avoid redefinition error C231

Hi Is any compiler command to avoid redefinition error C231 ? p.s. http://www.keil.com/support/man/docs/c51/c51_c231.htm
avoid redefinition error C231

Hi Is any compiler command to avoid redefinition error C231 ? p.s. http://www.keil.com/support/man/docs/c51/c51_c231.htm
Error C231: redefinition (of _getkey)

Hello all, After upgrading from an ancient version of C51 to the latest greatest V8.05A, legacy code does not compile any longer because: Build target 'Target 1' assembling STARTUP.A51... compiling...
Error C231: redefinition (of _getkey)

Hello all, After upgrading from an ancient version of C51 to the latest greatest V8.05A, legacy code does not compile any longer because: Build target 'Target 1' assembling STARTUP.A51... compiling...
I get error redefinition when I use target device DS87C550

I write a program using Keil C for 89C52. This program is successfully compiled. But when I choose another microcontroller (DS87C550), but I still keep the same program ( I just change the hearder file...