请教!!!编译时出现以下问题(50分)

--------------------Configuration: WinMain - Win32 Debug--------------------
Compiling...
WinMain.cpp
Linking...
LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
Debug/WinMain.exe : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.
WinMain.exe - 2 error(s), 0 warning(s)

没有main()函数.