var source_platform = '' , pf_source = 2; //系统平台

    //区别是否是 微信浏览器 , source_platform 系统平台  2018.12.6新增

    var ua = navigator.userAgent, source_platform = '';

    if (ua.match(/MicroMessenger/i) == 'MicroMessenger'){

        //微信浏览器

        source_platform = 'weixin';

        pf_source = 3;

    }else {

        source_platform = 'H5';

        pf_source = 2;

    }