ReleaseCapture - Win32 API reference

From HashVB

The ReleaseCapture function releases the mouse capture from a window in the current thread and restores normal mouse input processing. A window that has captured the mouse receives all mouse input, regardless of the position of the cursor, except when a mouse button is clicked while the cursor hot spot is in the window of another thread.

Declaration

Declare Function ReleaseCapture Lib "user32" () As Long