set -g prefix C-a

unbind-key C-b
bind-key C-a send-prefix

set-window-option -g mode-keys vi
unbind-key j
bind-key j select-pane -L
unbind-key k
bind-key k select-pane -R
unbind-key h
bind-key h select-window -n
unbind-key l
bind-key l select-window -p