_play_length->Changed.connect (boost::bind (&TimingPanel::play_length_changed, this));
_video_frame_rate->Bind (wxEVT_COMMAND_TEXT_UPDATED, boost::bind (&TimingPanel::video_frame_rate_changed, this));
_set_video_frame_rate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&TimingPanel::set_video_frame_rate, this));
_play_length->Changed.connect (boost::bind (&TimingPanel::play_length_changed, this));
_video_frame_rate->Bind (wxEVT_COMMAND_TEXT_UPDATED, boost::bind (&TimingPanel::video_frame_rate_changed, this));
_set_video_frame_rate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&TimingPanel::set_video_frame_rate, this));