if (!Array.prototype.indexOf)
{
	Array.prototype.indexOf = function(searchElement, fromIndex)
	{
		var l = this.length, i = 0;
		if (fromIndex)
		{
			i = fromIndex;
			if (i < 0)
			{
				i += l;
				if (i < 0) i = 0;
			}
		}

		while (i < l)
		{
			if (this[i] === searchElement) return i;
			i++;
		}

		return -1;
	}
}

function addClass(element, className)
{
	if (element.className.length)
	{
		var classes = getClassList(element);
		if (classes.indexOf(className) == -1)
		{
			classes.push(className);
			setClassList(element, classes);
		}
	}
	else
		element.className = className;
}

function removeClass(element, className)
{
	var classes = getClassList(element), index;
	if ((index = classes.indexOf(className)) > -1)
	{
		delete classes[index];
		setClassList(element, classes);
	}
}

function replaceClass(element, oldclass, newclass)
{
	var classes = getClassList(element), index;
	if ((index = classes.indexOf(oldclass)) > -1 && classes.indexOf(newclass) == -1)
	{
		classes[index] = newclass;
		setClassList(element, classes);
	}
}

function hasClass(element, className)
{
	var elementClassName = element.className;
	return	elementClassName.length &&
		(	elementClassName == className ||
			getClassRegExp(className).test(elementClassName)
		);
}

function getClassList(element)
{
	return element.className.length ? element.className.split(/\s+/) : [];
}

function setClassList(element, classes)
{
	element.className = classes.join(' ');
}

var regExpCache = {};
function getClassRegExp(className)
{
	if (!(className in regExpCache))
		regExpCache[className] = new RegExp('(^|\\s)' + className + '(\\s|$)');

	return regExpCache[className];
}