next_buffer Switch to the next buffer in buffer list.

    This command causes the current window to switch to the next buffer
    in the buffer list.  This command will not switch to a kill buffer 
    or to some other temporary buffer.

next_previous_buffer    Switch to previous buffer in buffer list.

    This command causes the current window to switch to the previous
    buffer in the current buffer list.  This command will not switch
    to a kill buffer or some other temporary buffer.