/*
Class: baseUtility

Overview: baseUtility Overview
	Basic, highly-useful utility functions.

Bugs:
	None known.
	
To do:
	None.

Change Log:
	2006.07.11 JEM	- Initial version.
*/

var domCompat = (document.getElementById) && (document.documentElement); // test for essential DOM compatability

// written by Dean Edwards, 2005
// with input from Tino Zijdel - crisp@xs4all.nl
// http://dean.edwards.name/weblog/2005/10/add-event/
// http://therealcrisp.xs4all.nl/upload/addEvent_dean.html
function addEvent(element, type, handler)
{
	if (element.addEventListener)
		element.addEventListener(type, handler, false);
	else
	{
		if (!handler.$$guid) handler.$$guid = addEvent.guid++;
		if (!element.events) element.events = {};
		var handlers = element.events[type];
		if (!handlers)
		{
			handlers = element.events[type] = {};
			if (element['on' + type]) handlers[0] = element['on' + type];
			element['on' + type] = handleEvent;
		}
	
		handlers[handler.$$guid] = handler;
	}
}
addEvent.guid = 1;

function removeEvent(element, type, handler)
{
	if (element.removeEventListener)
		element.removeEventListener(type, handler, false);
	else if (element.events && element.events[type] && handler.$$guid)
		delete element.events[type][handler.$$guid];
}

function handleEvent(event)
{
	event = event || fixEvent(window.event);
	var returnValue = true;
	var handlers = this.events[event.type];

	for (var i in handlers)
	{
		if (!Object.prototype[i])
		{
			this.$$handler = handlers[i];
			if (this.$$handler(event) === false) returnValue = false;
		}
	}

	if (this.$$handler) this.$$handler = null;

	return returnValue;
}

function fixEvent(event)
{
	event.preventDefault = fixEvent.preventDefault;
	event.stopPropagation = fixEvent.stopPropagation;
	return event;
}
fixEvent.preventDefault = function()
{
	this.returnValue = false;
}
fixEvent.stopPropagation = function()
{
	this.cancelBubble = true;
}

// This little snippet fixes the problem that the onload attribute on the body-element will overwrite
// previous attached events on the window object for the onload event
if (!window.addEventListener)
{
	document.onreadystatechange = function()
	{
		if (window.onload && window.onload != handleEvent)
		{
			addEvent(window, 'load', window.onload);
			window.onload = handleEvent;
		}
	}
}

/* 
Function: window.prototype.print
	Displays an error message to the user who is trying to execute a script that uses window.print in a browser that does not support window.print.

Parameters:
	None.

Dependencies:
	None.

Bugs:
	None known.
	
To do:
	None.

Change Log:
	2006.07.11	JEM	- Initial version.
*/
if (window.print == null) {
	window.print = function() {
		alert("Sorry, this browser does not support this function.  Please print this page as you normally would.");
	}
}

/* 
Function: $
	Shortcut function for document.getElementById.  Adapted from Prototype framework library.

Parameters:
	None.

Dependencies:
	None.

Bugs:
	None known.
	
To do:
	None.

Change Log:
	2007.07.11	JEM	- Initial version.
*/
function $(element) {
  if (typeof element == 'string') {
  	element = document.getElementById(element);
	}
  return element;
}