Sr. Antonio,
METHOD KeyDown( nKey, nFlags )
...
//----------------------------------------------------------------------------//
METHOD KeyDown( nKey, nFlags ) CLASS TBtnFlat
do case
case nKey == VK_UP .or. nKey == VK_LEFT
::oWnd:GoPrevCtrl( ::hWnd )
case nKey == VK_DOWN .or. nKey == VK_RIGHT
::oWnd:GoNextCtrl( ::hWnd )
endcase
return ::Super:KeyDown( nKey, nFlags )