function get_tags_by_class(tagname, classname)
{
	var tags = document.getElementsByTagName(tagname);
	var testClass = new RegExp("(^|\\s)" + className + "(\\s|$)");
	var tag, i;
	
	var result = [];
	for (i = 0; tag = tags[i]; i++)
		if (testClass.test(tag.className)) result.push(tag);
		
	return result;
}

// ultra simple event adding functions. use these only when you're not certain
// whether or not the DOM object might already have an event.
// if you know that it doesn't better just set the .onclick property of the
// object, because these functions do not point the this keyword to the original
// object in IE.

function addEventSimple(obj,evt,fn) {
	if (obj.addEventListener)
		obj.addEventListener(evt,fn,false);
	else if (obj.attachEvent)
		obj.attachEvent('on'+evt,fn);
}

function removeEventSimple(obj,evt,fn) {
	if (obj.removeEventListener)
		obj.removeEventListener(evt,fn,false);
	else if (obj.detachEvent)
		obj.detachEvent('on'+evt,fn);
}

// remember to remove this alias when using prototype.js

function $(id) { return document.getElementById(id) }