/* Reference Article:
Dustin Diaz:
http://www.dustindiaz.com/top-ten-javascript/
*/

/* addEvent: simplified event attachment */
function addEvent(obj, type, fn) {
    if (obj.addEventListener) {
        obj.addEventListener(type, fn, false);
        EventCache.add(obj, type, fn);
    }
    else if (obj.attachEvent) {
        obj["e" + type + fn] = fn;
        obj[type + fn] = function() {
            obj["e" + type + fn](window.event);
        }
        obj.attachEvent("on" + type, obj[type + fn]);
        EventCache.add(obj, type, fn);
    }
    else {
        obj["on" + type] = obj["e" + type + fn];
    }
}

var EventCache = function() {
    var listEvents = [];
    return {
        listEvents : listEvents,
        add : function(node, sEventName, fHandler) {
            listEvents.push(arguments);
        },
        flush : function() {
            var i, item;
            for (i = listEvents.length - 1; i >= 0; i = i - 1) {
                item = listEvents[i];
                if (item[0].removeEventListener) {
                    item[0].removeEventListener(item[1], item[2], item[3]);
                }
                ;
                if (item[1].substring(0, 2) != "on") {
                    item[1] = "on" + item[1];
                }
                ;
                if (item[0].detachEvent) {
                    item[0].detachEvent(item[1], item[2]);
                }
                ;
                item[0][item[1]] = null;
            }
            ;
        }
    };
}();
addEvent(window, 'unload', EventCache.flush);

/* window 'load' attachment */
function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
        window.onload = func;
    }
    else {
        window.onload = function() {
            oldonload();
            func();
        }
    }
}

/* grab Elements from the DOM by className */
function getElementsByClass(searchClass, node, tag) {
    var classElements = new Array();
    if (node == null)
        node = document;
    if (tag == null)
        tag = '*';
    var els = node.getElementsByTagName(tag);
    var elsLen = els.length;
    var pattern = new RegExp("(^|\\s)" + searchClass + "(\\s|$)");
    for (i = 0,j = 0; i < elsLen; i++) {
        if (pattern.test(els[i].className)) {
            classElements[j] = els[i];
            j++;
        }
    }
    return classElements;
}

/* toggle an element's display */
function toggle(obj) {
    var el = document.getElementById(obj);
    if (el.style.display != 'none') {
        el.style.display = 'none';
    }
    else {
        el.style.display = '';
    }
}

/* show an element */
function show(el) {
    el.style.display = '';
}

/* hide an element */
function hide(el) {
    el.style.display = 'none';
}

/* insert an element after a particular node */
function insertAfter(parent, node, referenceNode) {
    parent.insertBefore(node, referenceNode.nextSibling);
}

/* Array prototype, matches value in array: returns bool */
Array.prototype.inArray = function (value) {
    var i;
    for (i = 0; i < this.length; i++) {
        if (this[i] === value) {
            return true;
        }
    }
    return false;
};

/* get, set, and delete cookies */
function getCookie(name) {
    var start = document.cookie.indexOf(name + "=");
    var len = start + name.length + 1;
    if (( !start ) && ( name != document.cookie.substring(0, name.length) )) {
        return null;
    }
    if (start == -1) return null;
    var end = document.cookie.indexOf(";", len);
    if (end == -1) end = document.cookie.length;
    return unescape(document.cookie.substring(len, end));
}

function setCookie(name, value, expires, path, domain, secure) {
    var today = new Date();
    today.setTime(today.getTime());
    if (expires) {
        expires = expires * 1000 * 60 * 60 * 24;
    }
    var expires_date = new Date(today.getTime() + (expires));
    document.cookie = name + "=" + escape(value) +
                      ( ( expires ) ? ";expires=" + expires_date.toGMTString() : "" ) + //expires.toGMTString()
                      ( ( path ) ? ";path=" + path : "" ) +
                      ( ( domain ) ? ";domain=" + domain : "" ) +
                      ( ( secure ) ? ";secure" : "" );
}

function deleteCookie(name, path, domain) {
    if (getCookie(name)) document.cookie = name + "=" +
                                           ( ( path ) ? ";path=" + path : "") +
                                           ( ( domain ) ? ";domain=" + domain : "" ) +
                                           ";expires=Thu, 01-Jan-1970 00:00:01 GMT";
}

/* quick getElement reference */
function $() {
    var elements = new Array();
    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];
        if (typeof element == 'string')
            element = document.getElementById(element);
        if (arguments.length == 1)
            return element;
        elements.push(element);
    }
    return elements;
}

function LTrim(str) {
    if (str == null) {
        return null;
    }
    for (var i = 0; str.charAt(i) == " "; i++);
    return str.substring(i, str.length);
}
function RTrim(str) {
    if (str == null) {
        return null;
    }
    for (var i = str.length - 1; str.charAt(i) == " "; i--);
    return str.substring(0, i + 1);
}

function Trim(str) {
    return LTrim(RTrim(str));
}

function isNull(val) {
    return(val == null);
}

function isEmpty(element) {
    return ( (isNull(element) || (Trim(element.value).length == 0) ));
}