# File control/SetupAlias/SetupAlias.rb, line 6
  def init_context
    @driver = driver
    @pos = @driver.params['pos'].to_i
    @control = page_option(:control)
    @list = @control.aliases
    len = @list.length
    if (0 <= @pos && @pos < len) then
      # nothing to do.
    elsif (@pos == len) then
      @list.add_entry
    else
      raise 'out of range'
    end
    @params = @list[@pos]
  end