function MathHelp() {
    this.Sum = function(list) {
        return eval(list.join("+"));
    }
    this.Avg = function(list, fixed) {
        return Divide(this.Sum(list), list.length, fixed);
    }
    this.Divide = function(dividend, divisor, fixed) {
        if (isNaN(divisor) || divisor === 0)
            return 0;
        var reValue = dividend / divisor;
        if (isNaN(fixed))
            return reValue;
        else return reValue.toFixed(fixed);
    }
}
function VerifyHelp() {
    this.IsArray=function(o) {
        return Object.prototype.toString.call(o) === '[object Array]';
    }
    this.IsNum=function (s) {
        if (s != null && s != "") {
            return !isNaN(s);
        }
        return false;
    }
}

function $(q, o) {
    if (typeof (q) !== 'string' || q == '') return [];
    var ss = q.split(' ');
    var attr = '';
    var s = ss[0].split(':')[0];
    if (s != ss[0])
        attr = ss[0].split(':')[1];

    var val = s.split('[')[0];
    if (val != s)
        val = s.split('[')[1].replace(/[",\]]/g, '');
    else
        val = '';
    s = s.split('[')[0];

    var obj = [];
    var sObj = null;

    o = o || document;
    switch (s.charAt(0)) {
        case '#':
            sObj = document.getElementById(s.substr(1));
            if (sObj) obj.push(sObj);
            break;
        case '.':
            var l = o.getElementsByTagName('*');
            var c = s.substr(1);
            for (var i = 0; i < l.length; i++)
                if (l[i].className.search('\\b' + c + '\\b') != -1) obj.push(l[i]);
            break;
        default:
            obj = o.getElementsByTagName(s);
            break;
    }

    if (val) {
        var l = [];
        var a = val.split('=');
        for (var i = 0; i < obj.length; i++) {
            switch (a.length) {
                case 1: if (obj[i].getAttribute(a[0]) != null) l.push(obj[i]); break;
                case 2: if (obj[i].getAttribute(a[0]) == a[1]) l.push(obj[i]); break;
            }
        }
        obj = l;
    }

    if (attr) {
        var l = [];
        for (var i = 0; i < obj.length; i++)
            if (obj[i][attr]) l.push(obj[i]);
        obj = l;
    }

    if (ss.length > 1) {
        var l = [];
        for (var i = 0; i < obj.length; i++) {
            var ll = arguments.callee(q.substr(ss[0].length + 1), obj[i]);
            if (ll.tagName) l.push(ll);
            else
                for (var j = 0; j < ll.length; j++) l.push(ll[j]);
        }
        obj = l;
    }

    if (sObj && ss.length == 1) {
        obj = sObj;
        if (obj) obj.length = 1;
    } else {
        var l = [];
        for (var i = 0; i < obj.length; i++) obj[i].$isAdd = false;
        for (var i = 0; i < obj.length; i++) {
            if (!obj[i].$isAdd) {
                obj[i].$isAdd = true;
                l.push(obj[i]);
            }
        }
        obj = l;
    }

    return obj;
}