getParentByTagName - Get parent node for given tagname

getParentByTagName.js

/**
 * Get parent node for given tagname
 * @param  {Object} node    DOM node
 * @param  {String} tagname HTML tagName
 * @return {Object}         Parent node
 */
function getParentByTagName(node, tagname) {
	var parent;
	if (node === null || tagname === '') return;
	parent  = node.parentNode;
	tagname = tagname.toUpperCase();

	while (parent.tagName !== "HTML") {
		if (parent.tagName === tagname) {
			return parent;
		}
		parent = parent.parentNode;
	}

	return parent;
}