if Error_message then
    local height = math.min(20*Editor_state.line_height, App.screen.height*0.2)
    App.color{r=0.8,g=0,b=0}
    love.graphics.rectangle('fill', 150, App.screen.height - height-10, App.screen.width, height+10)
    App.color{r=0,g=0,b=0}
    love.graphics.print(Error_message, 150+10, App.screen.height - height)
  end
end
function source.update(dt)
  Cursor_time = Cursor_time + dt
  if App.mouse_x() < Editor_state.right then
    edit.update(Editor_state, dt)
  elseif Show_log_browser_side then
    log_browser.update(Log_browser_state, dt)
  end
end
function source.quit()
  edit.quit(Editor_state)
  log_browser.quit(Log_browser_state)

      -- preserve any Error_message when going from run to source
      Error_message = nil