1 /**

     2  * Makes "skip to content" link work correctly in IE9, Chrome, and Opera

     3  * for better accessibility.

     4  *

     5  * @link http://www.nczonline.net/blog/2013/01/15/fixing-skip-to-content-links/

     6  */

     7 

     8  ( function() {

     9 	var isWebkit = navigator.userAgent.toLowerCase().indexOf( 'webkit' ) > -1,

    10 		isOpera  = navigator.userAgent.toLowerCase().indexOf( 'opera' )  > -1,

    11 		isIE     = navigator.userAgent.toLowerCase().indexOf( 'msie' )   > -1;

    12 

    13 	if ( ( isWebkit || isOpera || isIE ) && document.getElementById && window.addEventListener ) {

    14 		window.addEventListener( 'hashchange', function() {

    15 			var id = location.hash.substring( 1 ),

    16 				element;

    17 

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

    19 				return;

    20 			}

    21 

    22 			element = document.getElementById( id );

    23 

    24 			if ( element ) {

    25 				if ( ! ( /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) ) {

    26 					element.tabIndex = -1;

    27 				}

    28 

    29 				element.focus();

    30 

    31 				// Repositions the window on jump-to-anchor to account for admin bar and border height.

    32 				window.scrollBy( 0, -53 );

    33 			}

    34 		}, false );

    35 	}

    36 } )();