Set a focus to a button

[reptile]

I want t set a focus on a button. When I use the shown code in MFC for an edit control:

::SetFocus(
    ::GetDlgItem(
        GetSafeHwnd(), // HWND of the dialog window
        <id> ) );

everything goes OK. But when I try it for a button it failes.
However this code:

GetDlgItem( <id> )->SetFocus();

works well in both cases. What is the difference.

At last, what I must to do to set focus to a button in WINAPI, if my method is wrong?