GUICtrlOnHover library allows to set event function for the window control hover process. Syntax: _GUICtrl_OnHoverRegister(ControlID [, OnHoverFunc [, OnLeaveHoverFunc [, PrimaryDownFunc [, PrimaryUpFunc [, KeepCall_PrDn_Func [, KeepCall_Hover_Func]]]]]]) ControlID can be -1 as in Build-In functions! Example: #include "GUICtrlOnHover.au3"Opt("GUIOnEventMode", 1)$Btn_Color = 0x7A9DD8$Hover_Color = 0xFF0000 ;0x7AC5D8$GUIMain = GUICreate("Letters Hovering Example", 570, 200)GUISetOn