ajaxtoolkit autocomplete extender CompletionListItemCssClass change

Hello..

I am using ajaxtoolkit autocomplete in a dictionary project and when I type it show the suggestion and it is(Direction:ltr) and I want to change it to (Direction:rtl) from a javascript function but I am not successed and this my code:

ajaxtoolkit:

<asp:AutoCompleteExtender ID="autocom"  ClientIDMode="Static"  runat="server" CompletionSetCount="10" CompletionListElementID="list"   CompletionListItemCssClass="toolkitEnglish"
                EnableCaching="true" MinimumPrefixLength="1" TargetControlID="txtBoxWord"   ServicePath="~/translator/AutoComplete.asmx" ServiceMethod="GetCompletionList"  ></asp:AutoCompleteExtender>

and this is my JS code:

<script type="text/javascript">
          var index = 0;
          function IndexChanged() {
              index = comboboxLang.GetSelectedIndex();
              if (index == 0) {$("#txtBoxWord").css("direction", "ltr");$("#txtBoxWord").val("");$find('autocom').set_contextKey("1");$find('list').set_CompletionListItemCssClass("toolkitEnglish");

                  //$("#list").removeClass("toolkitKurdish");

                  //$("#list").addClass("toolkitEnglish");
              }
              if (index == 1) {$("#txtBoxWord").css("direction", "rtl");$("#txtBoxWord").val("");$find('autocom').set_contextKey("2");$find('list').set_CompletionListItemCssClass("toolkitKurdish");

                  //$("#list").removeClass("toolkitEnglish");
                  //$("#list").addClass("toolkitKurdish");

              }
          }

            </script>

Thank you