编译出错,求教,该怎么解决

编译出错,求教
error LNK2001: unresolved external symbol "public: long __thiscall CMainDlg::OnStop(unsigned short,unsigned short,struct HWND__ *,int &)" (?OnStop@CMainDlg@@QAEJGGPAUHWND__@@AAH@Z)
1>Debug\freescale console.exe : fatal error LNK1120: 1 unresolved externals


这个程序是用WTL基于dialog写的,我想添加个按钮,在BEGIN_MSG_MAP(CMainDlg)下添加COMMAND_ID_HANDLER(IDC_STOP, OnStop)
但是链接时出现上错误,求教!

------解决方案--------------------
CMainDlg::OnStop
你好像实现了一个全局函数OnStop,而不是CMainDlg的OnStop