prototype.each_element_invoke.js

// Helper method for Prototype to loop over a collection of elements
// and run a method on existing elements within the dom
Object.extend(Array.prototype, {
	each_element_invoke: function(method) {
		var args = $A(arguments).slice(1);
		return this.map(function(element) {
			return element && element[method].apply(element, args);
		});
	}
});