MouseClick(API)

--MouseClick
function click(x1,y1,x2,y2)

  local event,button,x,y = os.pullEvent()
  if event == "mouse_click" then
    if x1 == "get" then
      return x,y
    elseif x1 == nil or y1 == nil then
      return true
    else
      x1 = tonumber(x1)
      y1 = tonumber(y1)
      x2 = tonumber(x2)
      y2 = tonumber(y2)
      if x > x1 - 1 and x < x2 + 1 and y > y1 - 1 and y < y2 + 1 then
        return true
      else
        return false
      end
    end
  end
end