Menu event not working

Hi
i am making a dialog based project in MFC using VS2005. The problem is that i am craeting menu on button click As a click a button menu is open properly. but if i am given control on that pop up menu nothing happen.
i am giving some code.
plz help me.

this is the code on button click event

CMenu *pContextMenu=NULL ;
pContextMenu = menu.GetSubMenu (0);


CWnd* pWnd = GetDlgItem(IDC_NETSTAG);

if ( !pWnd )

return ;

CRect rect;

pWnd->GetWindowRect( &rect );

// Show the Menu

int nCmd = pContextMenu->TrackPopupMenu (TPM_LEFTALIGN |

TPM_RETURNCMD,

rect.left, rect.bottom,
AfxGetMainWnd() );


this is the code on menu handler

CSampleDlg::OnLogin
{

AfxMessageBox ("Baher jao");//this is not fire after displaing opup menu.

}


thanks .