问如何关闭地图和文本框

EN

 local obj = display.newImageRect( "closeButton.jpg" ,25,25 )
            obj.x = 60
            obj.y = 410     -- replaced with newImageRect for dynamic scaling (adjust X & Y as required)

    obj.touch = function (event)
             local btn = event.target
                if event.phase == "ended" then 
                btn.alpha = 0  -- example to show the function doing something
                myMap.alpha = 0
                textBox.alpha = 0
            end

    end

    -- begin detecting touches
    obj:addEventListener( "touch", obj.touch)

myMap = native.newMapView( 25, 0, 275, 180 )
myMap.mapType = "hybrid" -- other mapType options are "satellite" or "hybrid"
myMap.isScrollEnabled = true
myMap.isZoomEnabled = true 
myMap.isLocationUpdating = true
isVisible = myMap.isLocationVisible
myMap:setCenter( 38.354614, -81.726351 )
myMap:addMarker(  38.354614, -81.726351)
-- Adding the Text Box that contains the Directions
textBox = native.newTextBox( 22, 183, 280, 225 )
textBox.text = "blah blah blah boring directions."
local group = display.newGroup()
group:insert( obj )