referer recognition

function referer(){
        engines =
        [
            {start:'http://www.google.', query:'q', name:'google'},
            {start:'http://yandex.', query:'text', name:'yandex'},
            {start:'rambler.ru/search', query:'query', name:'rambler'},
            {start:'http://go.mail.ru/', query:'q', name:'mailru'},
            {start:'http://www.bing.com/', query:'q', name:'bing'},
            {start:'search.yahoo.com/search', query:'p', name:'yahoo'},
            {start:'http://ru.ask.com/', query:'q', name:'ask'},
            {start:'http://search.qip.ru/search', query:'query', name:'qip'}
        ];

        var ref=document.referrer,req="",engine="", start;

        for (var i in engines){
            if  (!engines.hasOwnProperty(i))
                continue;
            if (ref.indexOf(engines[i].start)==-1)
                continue;
            start = ref.indexOf('?' + engines[i].query + '=')
            if (start == -1){
                start = ref.indexOf('&' + engines[i].query + '=');
                if (start == -1)
                    return false;
            }
            engine = engines[i].name;
            req = engines[i].query;
        }

        ref = ref.substr(start + req.length + 2);
        var end = ref.indexOf('&');
        if (end != -1)
                ref = ref.substr(0, end);
        return {"engine": engine, "query": ref};
}