function getOpeningTagFromPosition(html, pos) {
						var m;
						if (html.charAt(pos) == '<' && (m = html.substring(pos, html.length).match(startTag))) {
							return range(pos, m[0]);
						}
					}
@param {String} html Where to search tag
@param {Number} pos Character index where to start searching
@return {Range} Returns range if valid opening tag was found,
<code>null</code> otherwise