AutoComplete Textbox

Question

Hi guys, i am trying to do the auto complete textbox using entity data model but i am getting this error "parsererror"  please help, bellow is my code:

 

 

aspx Code

 

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="AutoComplete._Default" %>

<asp:Content runat="server" ID="FeaturedContent" ContentPlaceHolderID="FeaturedContent">
<link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css">
<script src="http://code.jquery.com/jquery-1.9.1.js"></script>
<script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>

<script lang="javascript" type="text/javascript">
$(function () {
$('#<%=txtCompanyName.ClientID%>').autocomplete({
source: function (request, response) {
$.ajax({
url: "Default.aspx/GetCompanyName",
data: "{'pre':'"+ request.term +"'}",
dataType: "json",
type: "POST",
constentType: "application/json; charset=utf-8",
success: function (data) {
response($.map(data.d,function(item)
{
return {value : item}
}))
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
alert(textStatus);
}
});
}
});

});
</script>

</asp:Content>
<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="MainContent">
<h3>Auto Complete</h3>
<table>
<tr>
<td>Type Company Name: </td>
<td>
<div class="ui-widget" style="text-align-last:left">
</div>
</td>
</tr>
</table>

<div class="ui-widget" style="text-align-last:left">
<asp:TextBox ID="txtCompanyName" runat="server" CssClass="textboxAuto" Width="350px" Font-Size="12px"></asp:TextBox>

</div>
</asp:Content>

 

aspx.cs Code

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Script.Services;
using System.Web.Services;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace AutoComplete
{
public partial class _Default : Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
[WebMethod]
[ScriptMethod(ResponseFormat= ResponseFormat.Json)]
public static List<string> GetCompanyName(string pre)
{
List<string> allCompanyName = new List<string>();
using (MyDatabaseEntities dc = new MyDatabaseEntities ())
{
allCompanyName = (from a in dc.TopCompanies
where a.CompanyName.StartsWith(pre)
select a.CompanyName).ToList();
}
return allCompanyName;
}
}
}