Javascriptでエンター移動する

$(function() {
       var elements = ":input[type=text]:visible:enabled,select:visible:enabled,textarea:visible:enabled";
       $(":input[type=text], select, textarea").keypress(function(e) {
           if (this.type == "textarea") {
             return;
           }
           var c = e.which ? e.which : e.keyCode;
           if (c == 13) {
             var jqObjects = $(elements);
             var index = jqObjects.index(this);
             if (index == -1) {
               return;
             }
             if (e.shiftKey) {
               index--;
             } else {
               index++;
             }
             var size = jqObjects.size();
             index = index % size;
             jqObjects.eq(index).focus();
             e.preventDefault();
           }
       });
   });