this linker error prevents me from launching my 800-line aircraft game!

[unholymight]

1>------ Build started: Project: sdg, Configuration: Debug Win32 ------
1>Compiling...
1>game.cpp
1>Linking...
1>game.obj : error LNK2019: unresolved external symbol "public: void __thiscall bullet::set_active(bool)" (?set_active@bullet@@QAEX_N@Z) referenced in function _WinMain@16
1>C:\Documents and Settings\xxx\sdg.exe : fatal error LNK1120: 1 unresolved externals
1>Build log was saved at "file://c:\Documents and Settings\xxx\BuildLog.htm"
1>sdg - 2 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

is there a linker setting i should change? i will provide more information

[md]

did you actually write the bullet:set_active() function? The error indicates that the function couldn't be found.

[unholymight]

You sir are my hero.