AutoCompleteExtender with WebService not working on Hosting?

I am using webservice to get the place list in my page. It's working fine on development machine but in hosting its not showing any result. How to fix this issue..

here is .aspx file

<label>Received From Customer</label><asp:TextBox ID="txtSendBy" TabIndex="3" runat="server" CssClass="form-control1" CausesValidation="false" AutoPostBack="true"></asp:TextBox><ajaxToolkit:AutoCompleteExtender ID="acFromCustomer" runat="server"
 TargetControlID="txtSendBy" MinimumPrefixLength="1" FirstRowSelected="true"
 EnableCaching="false" CompletionSetCount="10" CompletionInterval="10"
 ServiceMethod="GetServiceList"></ajaxToolkit:AutoCompleteExtender>

Here is code behind:

[System.Web.Script.Services.ScriptMethod()][System.Web.Services.WebMethod]publicstaticList<string>GetServiceList(string prefixText){ParcelBookingAccess parcelbookingAccess =newParcelBookingAccess();UserEntity userentity =newUserEntity();
        userentity =(UserEntity)HttpContext.Current.Session["UserSession"];DataTable dtPlace =newDataTable();
        dtPlace = parcelbookingAccess.GetServicePlaceList(prefixText, userentity.BranchId, userentity.CompanyId, userentity.isOperateServicePlace).Tables[0];List<string> placelist =newList<string>();for(int i =0; i <= dtPlace.Rows.Count-1; i++){
            placelist.Add(dtPlace.Rows[i][1].ToString());}return placelist;}