Button URl

Hi, How make button,when I click open app in google play ?

I want make it in g_ratebutton.

Thanks for Help.

function onCommonMenuLayerTouchEnded(touch, event)     local location = touch:getLocation()     cclog("onCommonMenuLayerTouchEnded: %0.2f, %0.2f", location.x, location.y)     touchBeginPoint = nil     if clickedButton ~= nil then         clickedButton:setPosition(cc.p(clickedButton:getPositionX(), clickedButton:getPositionY() + 3))                  if clickedButton == g\_rateButton then         elseif clickedButton == g\_playButton then             local gameScene = nil              if g\_initFlag == nil then                 gameScene = require("scripts.GameScene")             else                 gameScene = createGameScene()             end             local trans = cc.TransitionFade:create(0.5, gameScene, cc.c3b(0,0,0))             cc.Director:getInstance():replaceScene(trans)             cc.SimpleAudioEngine:getInstance():playEffect(uiPath)                  elseif clickedButton == g\_rankButton then             showAds()         end         clickedButton = nil     end end