The UDM_GETPOS message retrieves the current position of an up-down control.
UDM_GETPOS wParam = 0; lParam = 0;
The return value is the current position in the low-order word. If an error occurred, the high-order word is nonzero.
When processing this message, the up-down control updates its current position based on the caption of the buddy window. The up-down control returns an error if there is no buddy window or if the caption specifies an invalid or out-of-range value.