bind-key -T copy-mode-vi 'y' send -X copy-selection
bind-key -T copy-mode-vi 'Space' send -X halfpage-down
bind-key -T copy-mode-vi 'Bspace' send -X halfpage-up
bind-key -T copy-mode-vi 'y' send -X copy-selection
bind-key -T copy-mode-vi 'Space' send -X halfpage-down
bind-key -T copy-mode-vi 'Bspace' send -X halfpage-up