jquery随机数-www.

    $(function () {       
        function show() {
            var myurl = ['http://www./index.html', 'http://www./dmhao123.html', 'http://v.6.cn/event/qq/schuang.html', 'http://v.6.cn/event/qq/schuang.html'];
            //Math.random()*(上限-下限+1)+下限
            var i = parseInt(Math.random() * (3 - 0 + 1) + 0);
          
            var fr = $("#frt");
            fr.attr("src", myurl[i]);           
        }
        setInterval(show, 6000); // 注意函数名没有引号和括弧！        
    });