<script>
    function GetCurrentJumpUrl(){
        var eleLink  = document.getElementById('adLink');
        if(eleLink){
            var url = eleLink.getAttribute('href');
            //alert(url);
            window.external.OpenNewUrlInChrome(url);
            return false;
        }
        return false;
    }
</script>

<div class="main-box">
  
  <div class="cont">
    <!-- 这一段HTML是需要广告那边修改，加上id，加上 onclick事件 -->
   <a id="adLink" href="https://xxx.html" target="_blank"> <img src="https://xxx.jpg" alt="xxx" onclick="javascript: return GetCurrentJumpUrl();"></a>
  </div>
</div>