Autocomplete Web Service in ASP.Net web forms - asp.net

Question

I have a web service for multiple item selection, its working fine but i am getting Undefined data. anyone can tell me solution for it. I am attaching my error screenshot too with this post, please see them below.
Web Service JSON Code
<script type="text/javascript">
$(document).ready(function () {
SearchText();
});
function SearchText() {
$("[id*=ctl00_ContentMain_TextBoxSkills]").autocomplete({
source: function (request, response) {
$.ajax({
type: "POST",
contentType: "application/json; charset=utf-8",
url: '<%=ResolveUrl("WebServiceSkills.asmx/GetAutoCompleteData")%>',
data: "{'skill':'" + extractLast(request.term) + "'}",
dataType: "json",
success: function (data) {
response(data.d);
},
error: function (result) {
alert("No Result Found");
}
});
},
focus: function () {
// prevent value inserted on focus
return false;
},
select: function (event, ui) {
var terms = split(this.value);
// remove the current input
terms.pop();
// add the selected item
terms.push(ui.item.value);
// add placeholder to get the comma-and-space at the end
terms.push("");
this.value = terms.join(", ");
return false;
}
});
$("#ctl00_ContentMain_TextBoxSkills").bind("keydown", function (event) {
if (event.keyCode === $.ui.keyCode.TAB &&
$(this).data("autocomplete").menu.active) {
event.preventDefault();
}
})
function split(val) {
return val.split(/,\s*/);
}
function extractLast(term) {
return split(term).pop();
}
}
</script>
Web Service:
[WebMethod]
public List<UserRegistration> GetAutoCompleteData(string skill)
{
List<UserRegistration> list = new List<UserRegistration>();
UserRegistrationHelper userRegistrationHelper = new UserRegistrationHelper();
using (DataTable dataTable = userRegistrationHelper.GetSkillsList(skill))
{
if (CommonFunctions.ValidateDataTable(dataTable))
{
foreach (DataRow dr in dataTable.Rows)
{
var SkillsList = new UserRegistration
{
SkillId = Convert.ToInt32(dr["SkillId"].ToString()),
Skills=dr["SkillName"].ToString()
};
list.Add(SkillsList);
}
}
}
return list;
}
Screenshot here:

Answer 1

I got answer for it:
1: Change SQL Query:
select concat('[', STUFF
(
(
SELECT top 15 '","'+ CAST(skillname AS VARCHAR(MAX))
from DNH_Master_Skills where SkillName LIKE '%' + #SkillName + '%'
FOR XMl PATH('')
),1,2,''
),'"]')
2: Change JSON Code:
From: response(data.d); TO: response(Array.parse(data.d));
Now its working feeling happy.