This function is equivalent to the WinSendMsg function, in which the receiving window procedure is specified by means of the item identity of the child window and parent-window handle.

It does not return until the message has been processed by the dialog item, whose return value is returned in mresReply.

The call is equivalent to:

WinSendMsg (WinWindowFromID(hwndDlg, idItem), msgid, param1, param2, reply);

This function is valid for any window with children; however, it is typically used for dialog items in a dialog window.