bind the text and value in the text auto complete using JSON

aspx page 

 <td>

         <asp:TextBox CssClass="textbox_size" ID="txtspz" runat="server"></asp:TextBox>

          <cc1:AutoCompleteExtender ID="ace_spzname" runat="server" TargetControlID="txtspz"

           ServiceMethod="GetSpzList" MinimumPrefixLength="1" ServicePath="~/WebService/WebService1.asmx"

              EnableCaching="true" ShowOnlyCurrentWordInCompletionListItem="true" DelimiterCharacters=";,:"

                CompletionSetCount="5" CompletionInterval="0" FirstRowSelected="true" CompletionListCssClass="autocomplete"

                  CompletionListElementID="divwidth">

                     </cc1:AutoCompleteExtender>                     

     </td>

 <asp:Button ID="btnsubmit" OnClick="submit_btnclick" runat="server" Text="Submit" />

asmx.cs (use web service)

 [WebMethod]

        public string[] GetSpzList(string prefixText, int count)

        {

            using (DataClasses1DataContext dc = new DataClasses1DataContext())

            {

                var search = (from n in dc.Specialization  where n.Name.Contains(prefixText) select n.Name).ToArray();

                return search;

            }

        }

cs page 

protected void submit_btnclick(object sender, EventArgs e)

        {

string Gettext;

Gettext = txtspz.text;

}