def select_volume(evt):
    _select_x(evt, 'volume', 'face')
def select_edge(evt):
    _select_x(evt, 'edge', 'edge')
def select_face(evt):
    _select_x(evt, 'face', 'face')
def select_dot(evt):
    _select_x(evt, 'point', 'point')