function zebra(tagName, oddClass, evenClass)
{
	if (document.getElementsByTagName)
	{
		var allTags = document.getElementsByTagName(tagName);
		var newClass = '';
		var i;

		for(i = 0 ; i< allTags.length ; i++)
		{
			if((i%2) == 0)
				newClass = oddClass;
			else
				newClass = evenClass;
			if (allTags[i].className == '')
				allTags[i].className = newClass;
			else
				allTags[i].className = allTags[i].className + ' ' + newClass;
		}
	}
}