The mouse has left the bounds of the control
Member of Control (PRIM_CTRL)
MouseLeave is fired when the mouse leaves the outer bounds of a control. It is not fired on the parent when the mouse enters the bounds of a child control. Most MouseEnter/MouseLeave requirements, such as setting the cursor or Style, can be better managed through the use of other more automated features such as the MouseOverStyle property.
Febuary 18 V14SP2