The DM_REPOSITION message repositions a top-level dialog box so that it fits within the desktop area. An application can send this message to a dialog box after resizing it to ensure that the entire dialog box remains visible.
DM_REPOSITION
wParam = 0;
lParam = 0;
This message has no parameters.
This message has no return value.
This message has no effect if the dialog box is a child window.
Windows NT: Requires version 4.0 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winuser.h.
Dialog Boxes Overview, Dialog Box Messages