MQL5 ReferenceStandard LibraryPanels and DialogsCBmpButtonOnMouseDown CreateBorderBmpNamesBmpOffNameBmpOnNameBmpPassiveNameBmpActiveNamePressedLockingOnSetZOrderOnCreateOnShowOnHideOnMoveOnChangeOnActivateOnDeactivateOnMouseDownOnMouseUp OnMouseDown The virtual handler of control "MouseDown" event. virtual bool OnMouseDown() Return Value true - event processed, otherwise - false. OnDeactivate OnMouseUp