hwndDlg (HWND) - input

Parent-window handle.

idItem (ULONG) - input

Identity of the child window.

It must be greater or equal to 0 and less or equal to 0xFFFF.

msg (ULONG) - input

Message identity.

mp1 (MPARAM) - input

Message parameter 1.

mp2 (MPARAM) - input

Message parameter 2.

mresReply (MRESULT) - returns

Message-return data.