网页打开QQ

<a id="qq-web" alt="" href="http://wpa.qq.com/msgrd?v=3&uin=396980268&site=qq&menu=yes" target="_blank" class="clearfix">
            <span class="circle"><i class="i-qq"></i></span><h3>咨询在线客服</h3>
          </a>
          <script>
              if( $(window).width() > 500){
                $('#qq-web').attr('href','http://wpa.qq.com/msgrd?v=3&uin=396980268&site=qq&menu=yes');
                $('#qq-web').attr('alt',$(window).width());
              }else{
                $('#qq-web').attr('href','mqqwpa://im/chat?chat_type=wpa&uin=396980268&version=1&src_type=web&web_src=oicqzone.com');
                $('#qq-web').attr('alt',$(window).width());
              }
              // alert($(window).width());
          </script>