/**
 * File skip-link-focus-fix.js.
 * 
 * @package a5
 * @since   1.0
 * @author  AI5LE
 * @license GPL v3 or later
 * @link    http://www.ai5le.com/
 */
(function() {
	var isIe = /(trident|msie)/i.test( navigator.userAgent );

	if ( isIe && document.getElementById && window.addEventListener ) {
		window.addEventListener( 'hashchange', function() {
			var id = location.hash.substring( 1 ),
				element;

			if ( ! ( /^[A-z0-9_-]+$/.test( id ) ) ) {
				return;
			}

			element = document.getElementById( id );

			if ( element ) {
				if ( ! ( /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) ) {
					element.tabIndex = -1;
				}

				element.focus();
			}
		}, false );
	}
})();