Very Simple CSS Selector

gistfile1.js

/*!
 * Simple CSS Selector
 * Copyright(C) 2010 by Amin Akbari [ eAmin.js on gmail ]
 * Licenced under the MIT Style License [http://www.opensource.org/licenses/mit-license.php]
 * Created on: 1/22/2010
 */

var selector = function(query) {
	var trim = function(arg) { return arg.replace(/^\s+|\s+$/, ''); };
	var contains = function(arg1, arg2) { return arg1.indexOf(arg2) !== -1; };

	query = trim(query);
	var tag = document.getElementsByTagName('*'), length = tag.length, match = [], seperate = query.split(/,/g);

	for (var j = 0, leng = seperate.length; j < leng; j++) {
		var ele = trim(seperate[j]);
		if (contains(ele, '#'))  {
			for (var i = 0; i < length; i++) {
				if(tag[i].id === ele.slice(1)) match.push(tag[i]);
			}
		} else if (contains(ele, '.')) {
			for (var i = 0; i < length; i++) {
				if (contains(' '+tag[i].className+' ', ' '+ele.slice(1)+' '))
					match.push(tag[i]);
			}
		} else {
			for (var i = 0; i < length; i++ ) {
				if (tag[i].nodeName.toLowerCase() === ele) match.push(tag[i]);
			}
		}
	}

	return match;
}

use.js

window.onload = function() {

	var elems = selector('h1, #ids, .class1, p, span');
	for (var i = 0; i < elems.length; i++) {
		elems[i].style.color = '#8977FF';
		elems[i].style.fontFamily = 'verdana';
		elems[i].style.fontSize = '12px';
		elems[i].onmouseover = function() {
			this.style.color = '#FFFFFF';
			this.style.backgroundColor = '#000000';
		};
		elems[i].onmouseout = function() {
			this.style.color = '#8977FF';
			this.style.backgroundColor = '';
		}
	}

};