String.prototype.ltrim = function() {
    var re = /\s*((\S+\s*)*)/;
    return this.replace(re, "$1");
}

String.prototype.rtrim = function() {
    var re = /((\s*\S+)*)\s*/;
    return this.replace(re, "$1");
}

String.prototype.trim = function() {
    return this.ltrim().rtrim();
}


function $(id) {
    return document.getElementById(id);
}

function $V(id) {
    return $(id).value;
}

function $VB(id) {
    if ($V(id) == "")
        return false;
    else
        return true;
}

function $S(id) {
    return $(id).style;
}

function $parent(id) {
    return parent.document.getElementById(id);
}

function $parentV(id) {
    return $parent(id).value;
}

function $parentS(id) {
    return $parent(id).style;
}

function $opener(id) {
    return opener.document.getElementById(id);
}   

function $tagName(tagName) {
    return document.getElementsByTagName(tagName);
}

function $create(tagName) {
    return document.createElement(tagName);
}

function $appendchild(tagName, idx, childctl) {
    $tagName(tagName)[idx].appendChild(childctl);
}

function $removechild(tagName, idx, childctl) {
    $tagName(tagName)[idx].removeChild(childctl);
}

function QueryString(key) {

    if (location.href.indexOf("?") > -1) {
        var strQueryString = location.href.split('?')[1];

        var strValues = strQueryString.split("&");

        for (var i = 0; i < strValues.length; i++) {

            var strQueryKey = strValues[i].split("=")[0];
            var strQueryValue = strValues[i].split("=")[1];

            if (strQueryKey == key)
                return strQueryValue;
        }
    }

    return "";
}