Regra css em documento java script

[adavis 0]

Como inserir um trecho no código abaixo para que o input da função pegue uma classe .error do jquery validate??

 
<script type="text/javascript">
;(function( $ ) {
 
 // Browser supports HTML5 multiple file?
 var multipleSupport = typeof $('<input/>')[0].multiple !== 'undefined',
     isIE = /msie/i.test( navigator.userAgent );
 
 $.fn.customFile = function() {
 
   return this.each(function() {
 
     var $file = $(this).addClass('customfile'), // the original file input
         $wrap = $('<div class="customfile-wrap">'),
         $input = $('<input type="text" class="customfile-filename" />'),
         // Button that will be used in non-IE browsers
         $button = $('<button type="button" class="customfile-upload">Selecionar</button>'),
         // Hack for IE
         $label = $('<label class="customfile-upload" for="'+ $file[0].id +'">Selecionar</label>');
 
     // Hide by shifting to the left so we
     // can still trigger events
     $file.css({
       position: 'absolute',
       left: '-9999px'
     });
 
     $wrap.insertAfter( $file )
       .append( $file, $input, ( isIE ? $label : $button ) );
 
     // Prevent focus
     $file.attr('tabIndex', -1);
     $button.attr('tabIndex', -1);
 
     $button.click(function () {
       $file.focus().click(); // Open dialog
     });
 
     $file.change(function() {
 
       var files = [], fileArr, filename;
 
       // If multiple is supported then extract
       // all filenames from the file array
       if ( multipleSupport ) {
         fileArr = $file[0].files;
         for ( var i = 0, len = fileArr.length; i < len; i++ ) {
           files.push( fileArr[i].name );
         }
         filename = files.join(', ');
 
       // If not supported then just take the value
       // and remove the path to just show the filename
       } else {
         filename = $file.val().split('\\').pop();
       }
 
       $input.val( filename ) // Set the value
         .attr('title', filename) // Show filename in title tootlip
         .focus(); // Regain focus
 
     });
 
     $input.on({
       blur: function() { $file.trigger('blur'); },
       keydown: function( e ) {
         if ( e.which === 13 ) { // Enter
           if ( !isIE ) { $file.trigger('click'); }
         } else if ( e.which === 8 || e.which === 46 ) { // Backspace & Del
           // On some browsers the value is read-only
           // with this trick we remove the old input and add
           // a clean clone with all the original events attached
           $file.replaceWith( $file = $file.clone( true ) );
           $file.trigger('change');
           $input.val('');
         } else if ( e.which === 9 ){ // TAB
           return;
         } else { // All other keys
           return false;
         }
       }
     });
 
   });
 
 };
 
 // Old browser fallback
 if ( !multipleSupport ) {
   $( document ).on('change', 'input.customfile', function() {
 
     var $this = $(this),
         // Create a unique ID so we
         // can attach the label to the input
         uniqId = 'customfile_'+ (new Date()).getTime(),
         $wrap = $this.parent(),
 
         // Filter empty input
         $inputs = $wrap.siblings().find('.customfile-filename')
           .filter(function(){ return !this.value }),
 
         $file = $('<input type="file" id="'+ uniqId +'" name="'+ $this.attr('name') +'"/>');
 
     // 1ms timeout so it runs after all other events
     // that modify the value have triggered
     setTimeout(function() {
       // Add a new input
       if ( $this.val() ) {
         // Check for empty fields to prevent
         // creating new inputs when changing files
         if ( !$inputs.length ) {
           $wrap.after( $file );
           $file.customFile();
         }
       // Remove and reorganize inputs
       } else {
         $inputs.parent().remove();
         // Move the input so it's always last on the list
         $wrap.appendTo( $wrap.parent() );
         $wrap.find('input').focus();
       }
     }, 1);
 
   });
 }
 
}( jQuery ));
 
$('input[type=file]').customFile();
</script>
 
 

[adavis 0]

Alguém?