js统计网页在线时间的脚本

每xxxxx毫秒检测一次是否在线,
tr_count次之后设定改用户为假死状态(即不在当前页面活动,afk..)
当页面关闭时把停留时间送出,

/**//* ----------------------------------------------------------------------------
* script name: online.js
* last modified: 2008-4-13 22:25
* author: meyu
* copyright (c) 2008
* purpose: 跟踪在线时间
* ----------------------------------------------------------------------------*/

function tr_xmlhttpobject(url)...{
    this.xmlhttp=null;
    this.url=url;
    this.init=function()...{
        if(window.xmlhttprequest)...{
            this.xmlhttp=new xmlhttprequest();
        }else if(window.activexobject)...{
            this.xmlhttp=new activexobject("microsoft.xmlhttp");
        }
    };
    this.init();
    this.senddata=function(param)...{
        with(this.xmlhttp)...{
            open('get',this.url+(param||''),true);
            send(null);
        }
    };
}
if(/flag=flush/i.test(window.location.search))...{
    var tr_count=0;
    var tr_x=new tr_xmlhttpobject(window.location.href.replace(/&?(?:flush_count=)(d+)/i,
        function(a,d)...{
            tr_count=parseint(d);
            return "";
            })
    );
    function send()...{
        tr_count++;
        if(tr_count < 120)...{
            tr_x.senddata('&flush_count='+tr_count);
        }
    }
    window.setinterval(send,30000);
    window.onunload=function()...{tr_x.senddata('&flush_count='+tr_count);};
}