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

function $c(tagName, parent, className, innerHTML) {
	var elem = document.createElement(tagName);
	if ( parent    != null ) parent.appendChild( elem );
	if ( className != null ) elem.className = className;
	if ( innerHTML != null ) elem.innerHTML = innerHTML;
	return elem;
}

function addListener(el, sListener, fOnListener) {
	if(window.addEventListener){ // Mozilla, Netscape, Firefox
		el.addEventListener(sListener, fOnListener, false);
	}else{ // IE
		el.attachEvent('on'+sListener, fOnListener);
	}
}