how to Create Refresh button in Dialog box.

BOOL CALLBACK TcpDlgProc (HWND hTcpDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
     switch (message)
     {
     case WM_INITDIALOG :
		  GetTCPConn(hTcpDlg);// this is the function i am calling to get information in dialog box
		  return TRUE ;
          
     case WM_COMMAND :
          switch (LOWORD (wParam))
          {
          case IDOK :
			   EndDialog (hTcpDlg, 0);
			   return TRUE;

          case IDREFRESH :
// What should i do to refresh the content of dialog box
               return TRUE ;
          }
 
	 case WM_DESTROY:
		  EndDialog(hTcpDlg,0);
		  return TRUE ;
          break ;
     }
     return FALSE ;
}