做了个MFC的单文档的员工薪酬管理系统，运行出现了错误！求解决

Linking...
YUANGONGXINCHOUView.obj : error LNK2005: "protected: void __thiscall CYUANGONGXINCHOUView::OnButtonAdd(void)" (?OnButtonAdd@CYUANGONGXINCHOUView@@IAEXXZ) already defined in AddDlg.obj
AddDlg.obj : error LNK2001: unresolved external symbol "protected: void __thiscall CAddDlg::OnRecAdd(void)" (?OnRecAdd@CAddDlg@@IAEXXZ)
Debug/YUANGONGXINCHOU.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.