[Solved] Bug in RadAutocompletebox while working with webservice

[Uttam Dhakal]

I am working with radautocompletebox to fetch email addresses for a user from sharepoint userprofile. 
i have a webservice method created that returns the matching email address. 
the first time it works and when i search again for another user or same user whenever i type anything in the box it throws the erro called object refrence not set to an instance of object. but if i reload the page again then it works. 

here is the code for my webservices and the rad autocompletebox. 

//error i am getting at the browser when i type anything second time in the radautocompletebox...


SCRIPT5022: Sys.InvalidOperationException: Type Telerik.Web.UI.AttributeCollection has already been registered. The type may be defined multiple times or the script file that defines it may have already been loaded. A possible cause is a change of settings during a partial update.
ScriptResource.axd?d=QJ81aqhAwulu2hIOFMDEkrm2EPI_p5Rwn1qI6uFkGM6jPgRdNCdVCW-Ayu0H8f67BVUhz1dDf0p53SEzAsTbe86n4C8no9dnNoDIOecQwHTcrKnohckOhEi-82CZIS9S59Q-OnLMc6Zo--sMwRT5nIG_jACybbgI7netGoKwKlFGkZtn0&t=ffffffffb868b5f4, line 1717 character 42

SEC7115: :visited and :link styles can only differ by color. Some styles were not applied to :visited.





//web service method that returns the selected email address of the input typed in the radautcompletebox
[WebMethod]

public  AutoCompleteBoxData FilterEmailaddress(RadAutoCompleteContext context)

        {

            string prefixText = context.Text.ToString();



            List<AutoCompleteBoxItemData> result = new List<AutoCompleteBoxItemData>();

            AutoCompleteBoxData dropdowndata = new AutoCompleteBoxData();

            List<String> existingemailadd = UserEmailAddress();

            var q = from string s in existingemailadd

                    where s.ToLower().StartsWith(prefixText.ToLower().Trim())

                    select s;

            foreach (string s in q)

            {

                AutoCompleteBoxItemData itemdata = new AutoCompleteBoxItemData();

                itemdata.Text = s;

                itemdata.Value = s;

                result.Add(itemdata);



            }



            if (result.Count > 0)

            {

                dropdowndata.Items = result.ToArray();

            }



            return dropdowndata;

        }



//list returing the emailaddresses for all users from the userprofile

        private  List<String> UserEmailAddress()

        {

            List<String> emailaddress = new List<string>();

            HttpContext context = System.Web.HttpContext.Current;

            string protocol = context.Request.ServerVariables["HTTPS"].ToString().Equals("ON", StringComparison.CurrentCultureIgnoreCase) ? "https" : "http";

            string port = context.Request.ServerVariables["SERVER_PORT"].ToString();

            string server = context.Request.ServerVariables["Server_Name"].ToString();

            string address = string.Format("{0}://{1}:{2}", protocol, server, port);

            SPSecurity.RunWithElevatedPrivileges(delegate

                {

                    using (SPSite site = new SPSite(address))

                    {

                        try

                        {

                            SPServiceContext servicecontext = SPServiceContext.GetContext(site);

                            UserProfileManager userProfileManager = new UserProfileManager(servicecontext);

                            foreach (UserProfile user in userProfileManager)

                            {

                                string emailadd = (string)user["WorkEmail"].Value;

                                emailaddress.Add(emailadd);





                            }



                        }

                        catch (Exception ex)

                        {






                        }

                    }

                });



            return emailaddress;





        }




// Radautocompletebox in aspx

<telerik:RadAutoCompleteBox ID="RadAutoCompleteBox1" AllowCustomEntry="true"

                    DropDownHeight="150px" DropDownWidth="250px" runat="server" InputType="Text"

                    Filter="Contains">

                    <TextSettings SelectionMode="Single" />

                    <WebServiceSettings Path="/_layouts/WebServices/emailService.asmx"

                        Method="FilterEmailaddress" />

                </telerik:RadAutoCompleteBox>