// http://www.dustindiaz.com/getelementsbyclass/
function getElementsByClass(searchClass,node,tag) {
	var classElements = new Array();
	if ( node == null )
		node = document;
	if ( tag == null )
		tag = '*';
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp('(^|\\\\s)'+searchClass+'(\\\\s|$)');
	for (i = 0, j = 0; i < elsLen; i++) {
		if ( pattern.test(els[i].className) ) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
}

// addEvent and removeEvent, designed by Aaron Moore
// http://barney.gonzaga.edu/~amoore1/php/addEvent/
function addEvent(element, listener, handler) {
	//if the system is not set up, set it up, and
	// store any outside script's event registration in the first handler slot
	if(typeof element[listener] != 'function' || 
	typeof element[listener + '_num'] == 'undefined'){
		element[listener + '_num'] = 0;
		if(typeof element[listener] == 'function'){
			element[listener + 0] = element[listener];
			element[listener + '_num']++;
		}
		element[listener] = function(e){
			var r = true;
			e = (e) ? e : window.event;
			for(var i = 0; i < element[listener + '_num']; i++)
				if(element[listener + i](e) === false) r = false;
			return r;
		}
	}
	//if handler is not already stored, assign it
	for(var i = 0; i < element[listener + '_num']; i++)
		if(element[listener + i] == handler) return;
	element[listener + element[listener + '_num']] = handler;
	element[listener + '_num']++;
}

function removeEvent(element, listener, handler) {
	//if the system is not set up, or there are no handlers to remove, exit
	if(typeof element[listener] != 'function' || 
	typeof element[listener + '_num'] == 'undefined' ||
	element[listener + '_num'] == 0) return;
	//loop through handlers,
	//  if target handler is reached, begin overwriting each
	//  handler with the handler in front of it until one before the last
	var found = false;
	for(var i = 0; i < element[listener + '_num']; i++){
		if(!found)
			found = element[listener + i] == handler;
		if(found && (i+1) < element[listener + '_num'])
			element[listener + i] = element[listener + (i+1)];
	}
	//if handler was found, decrement the handler count
	if(found)
		element[listener + '_num']--;
}