(function() {
if(!window['JPG']) {
    window['JPG'] = {};
}

function isCompatible(other) {
    if( other===false 
        || !Array.prototype.push
        || !Object.hasOwnProperty
        || !document.createElement
        || !document.getElementsByTagName
        ) {
        alert('TR- if you see this message isCompatible is failing incorrectly.');
        return false;
    }
    return true;
}
window['JPG']['isCompatible'] = isCompatible;

/**
 * document.getElementById(); replacement.
 */
function $() {
    var elements = new Array();
    
    // Find all the elements supplied as arguments
    for (var i = 0; i < arguments.length; i++) {
        var element = arguments[i];
        
        // If the argument is a string assume it's an id
        if (typeof element == 'string') {
            element = document.getElementById(element);
        }
        
        // If only one argument was supplied, return the element immediately
        if (arguments.length == 1) {
            return element;
        }
        
        // Otherwise add it to the array
        elements.push(element);
    }
    
    // Return the array of multiple requested elements
    return elements;
};
window['JPG']['$'] = $;


/**
 * Register an event listener on an element
 */
function addEvent( node, type, listener ) {
    // Check compatibility using the earlier method
    // to ensure graceful degradation
    if(!isCompatible()) { return false }
    if(!(node = $(node))) return false;
    
    if (node.addEventListener) {
        // W3C method
        node.addEventListener( type, listener, false );
        return true;
    } else if(node.attachEvent) {
        // MSIE method
        node['e'+type+listener] = listener;
        node[type+listener] = function(){node['e'+type+listener]( window.event );}
        node.attachEvent( 'on'+type, node[type+listener] );
        return true;
    }
    
    // Didn't have either so return false
    return false;
};
window['JPG']['addEvent'] = addEvent;

/**
 * Unregister an event listener on an element
 */
function removeEvent(node, type, listener ) {
    if(!(node = $(node))) return false;
    if (node.removeEventListener) {
        node.removeEventListener( type, listener, false );
        return true;
    } else if (node.detachEvent) {
        // MSIE method
        node.detachEvent( 'on'+type, node[type+listener] );
        node[type+listener] = null;
        return true;
    }
    // Didn't have either so return false
    return false;
};
window['JPG']['removeEvent'] = removeEvent;

/**
 * Retrieve an array of element base on a class name
 */
function getElementsByClassName(className, tag, parent){
    parent = parent || document;
    if(!(parent = $(parent))) return false;
    
    // Locate all the matching tags
    var allTags = (tag == "*" && parent.all) ? parent.all : parent.getElementsByTagName(tag);
    var matchingElements = new Array();
    
    // Create a regular expression to determine if the className is correct
    className = className.replace(/\-/g, "\\-");
    var regex = new RegExp("(^|\\s)" + className + "(\\s|$)");
    
    var element;
    // Check each element
    for(var i=0; i<allTags.length; i++){
        element = allTags[i];
        if(regex.test(element.className)){
            matchingElements.push(element);
        }
    }
    
    // Return any matching elements
    return matchingElements;
};
window['JPG']['getElementsByClassName'] = getElementsByClassName;

/**
 * Toggle the style display value between none and the default
 */
function toggleDisplay(node, value) {
    if(!(node = $(node))) return false;
    if ( node.style.display != 'none' ) {
        node.style.display = 'none';
    } else {
        node.style.display = value || '';
    }
    return true;
}
window['JPG']['toggleDisplay'] = toggleDisplay;

/**
 * Insert a DOM node after another DOM node
 */
function insertAfter(node, referenceNode) {
    if(!(node = $(node))) return false;
    if(!(referenceNode = $(referenceNode))) return false;
    
    return referenceNode.parentNode.insertBefore(node, referenceNode.nextSibling);
};
window['JPG']['insertAfter'] = insertAfter;

/**
 * Remove all teh child nodes from an element
 */
function removeChildren(parent) {
    if(!(parent = $(parent))) return false;
    
    // While there is a child remove it
    while (parent.firstChild) {
         parent.firstChild.parentNode.removeChild(parent.firstChild);
    }
    // Return the parent again so you can stack the methods
    return parent;
};
window['JPG']['removeChildren'] = removeChildren;

/**
 * Insert a new node as the first child.
 */
function prependChild(parent,newChild) {
    if(!(parent = $(parent))) return false;
    if(!(newChild = $(newChild))) return false;
    if(parent.firstChild) {
        // There is already a child so insert before the first one
        parent.insertBefore(newChild,parent.firstChild);    
    } else {
        // No children so just append
        parent.appendChild(newChild);
    }
    // Return the parent again so you can stack the methods
    return parent;
} 
window['JPG']['prependChild'] = prependChild;

})();