Common Dialog - ID_FILE_SAVE

I need to be able to call the ID_FILE_SAVE from inside a function. How do I call "activate" ID_FILE_SAVE automatically from within a function, since it doesn't have a OnFileSave that I can see. My other question is about common dialogs. How do I call a commom dialog for instance the file open common dialog? Thanks for the help.

1)

SendMessage( WM_COMMAND, ID_FILE_SAVE );

2)

CFileDialog() dlg;
const int res = dlg.DoModal();
if (res == IDOK)
{
//do stuff
}