Get elements by class name - getElementsByClassName

gistfile1.js

/* Example usage:
	var widgets = getElementsByClassName(document, "a-css-classname");
	for (var i = 0; i < widgets.length; i++) {
		//Do something with widgets[i]
	}
*/

	function getElementsByClassName(node,classname) {
		if (node.getElementsByClassName) { 
			return node.getElementsByClassName(classname);
		} else {
			return (function getElementsByClass(searchClass,node) {
			if ( node == null )
				node = document;
			var classElements = [],
				els = node.getElementsByTagName("*"),
				elsLen = els.length,
				pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)"), i, j;

			for (i = 0, j = 0; i < elsLen; i++) {
				if ( pattern.test(els[i].className) ) {
					classElements[j] = els[i];
					j++;
				}
			}
			return classElements;
			})(classname, node);
		}
	}