(C-a <Tab>)
Move the input focus to the next region. This is done in a cyclic way so that the top region is selected after the bottom one. If no subcommand is given it defaults to `down'. `up' cycles in the opposite order, `top' and `bottom' go to the top and bottom region respectively. Useful bindings are (j and k as in vi)bind j focus down bind k focus up bind t focus top bind b focus bottom