Css for Auto copleted extender

 .completionList {

        border:solid 1px yellow;

        margin:0px;

        padding:3px;

        height: 120px;

        overflow:auto;

        background-color: yellow;    

        }

        .listItem {

        color: yellow;

        }

        .itemHighlighted {

        background-color:yellow;      

        }


Cs File for Auto completed extender

 [System.Web.Services.WebMethod]
     public static List<string> searcharea(string prefixText, int count)
     {

         List<string> areaname = new List<string>();
         SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["galagoconnection"].ToString());
         if (conn.State == ConnectionState.Closed)
         {
             conn.Open();
         }
         SqlDataAdapter adp = new SqlDataAdapter("select Area_Name from G_Service_Area where Area_Name like '" + prefixText + "'+'%'", conn);
         DataTable dtService = new DataTable();
         adp.Fill(dtService);
         if (dtService != null && dtService.Rows.Count > 0)
         {
             foreach (DataRow dr in dtService.Rows)
             {
                 areaname.Add(dr["Area_Name"].ToString());
             }
         }


         return areaname;
     }  
 .Aspx for AutoCompleted extender
  <asp:TextBox ID="txtarea" runat="server" width="100%"></asp:TextBox>
                                <cc1:AutoCompleteExtender ServiceMethod="searcharea" CompletionListCssClass="completionList over"
    MinimumPrefixLength="1"
    CompletionInterval="100" EnableCaching="false" CompletionSetCount="10"
    TargetControlID="txtarea"
    ID="AutoCompleteExtender3" runat="server" FirstRowSelected = "false" >
</cc1:AutoCompleteExtender>