append = function(html_container, html_element) {
			var pos = html_container.search(/(<\/[^>]+>\s*)$/);
			return html_container.substring(0, pos) + html_element + html_container.substring(pos);
		}
Appends an element as a child (with raw HTML).

@param {string} html_container
@param {string} html_element
@return {string}