attr: function( elem, name, value, pass ) {
 // don't set attributes on text and comment nodes
 if ( !elem || elem.nodeType === 3 || elem.nodeType === 8 ) {
 return undefined;
 }

 if ( pass && name in jQuery.attrFn ) {
 return jQuery(elem)[name](value);
 }

 var notxml = elem.nodeType !== 1 || !jQuery.isXMLDoc( elem ),
 // Whether we are setting (or getting)
 set = value !== undefined;

 // Try to normalize/fix the name
 name = notxml && jQuery.props[ name ] || name;

 // These attributes require special treatment
 var special = rspecialurl.test( name );

 // Safari mis-reports the default selected property of an option
 // Accessing the parent's selectedIndex property fixes it
 if ( name === "selected" && !jQuery.support.optSelected ) {
 var parent = elem.parentNode;
 if ( parent ) {
 parent.selectedIndex;

 // Make sure that it also works with optgroups, see #5701
 if ( parent.parentNode ) {
 parent.parentNode.selectedIndex;
 }
 }
 }

 // If applicable, access the attribute via the DOM 0 way
 // 'in' checks fail in Blackberry 4.7 #6931
 if ( (name in elem || elem[ name ] !== undefined) && notxml && !special ) {
 if ( set ) {
 // We can't allow the type property to be changed (since it causes problems in IE)
 if ( name === "type" && rtype.test( elem.nodeName ) && elem.parentNode ) {
 jQuery.error( "type property can't be changed" );
 }

 if ( value === null ) {
 if ( elem.nodeType === 1 ) {
 elem.removeAttribute( name );
 }

 } else {
 elem[ name ] = value;
 }
 }

 // browsers index elements by id/name on forms, give priority to attributes.
 if ( jQuery.nodeName( elem, "form" ) && elem.getAttributeNode(name) ) {
 return elem.getAttributeNode( name ).nodeValue;
 }

 // elem.tabIndex doesn't always return the correct value when it hasn't been explicitly set
 // http://fluidproject.org/blog/2008/01/09/getting-setting-and-removing-tabindex-values-with-javascript/
 if ( name === "tabIndex" ) {
 var attributeNode = elem.getAttributeNode( "tabIndex" );

 return attributeNode && attributeNode.specified ?
 attributeNode.value :
 rfocusable.test( elem.nodeName ) || rclickable.test( elem.nodeName ) && elem.href ?
 0 :
 undefined;
 }

 return elem[ name ];
 }

 if ( !jQuery.support.style && notxml && name === "style" ) {
 if ( set ) {
 elem.style.cssText = "" + value;
 }

 return elem.style.cssText;
 }

 if ( set ) {
 // convert the value to a string (all browsers do this but IE) see #1070
 elem.setAttribute( name, "" + value );
 }

 // Ensure that missing attributes return undefined
 // Blackberry 4.7 returns "" from getAttribute #6938
 if ( !elem.attributes[ name ] && (elem.hasAttribute && !elem.hasAttribute( name )) ) {
 return undefined;
 }

 var attr = !jQuery.support.hrefNormalized && notxml && special ?
 // Some attributes require a special call on IE
 elem.getAttribute( name, 2 ) :
 elem.getAttribute( name );

 // Non-existent attributes return null, we normalize to undefined
 return attr === null ? undefined : attr;
 }