ASP.NET

public ActionResult Index(){
  ViewBag.Clubs = db.Clubs.OrderByDescending(c => c.Name).ToList();
  ViewBag.Comps = db.Competitions.OrderByDescending(c => c.StartDate).ToList();
  ViewBag.Teams = db.Teams.OrderBy(t => t.Name).ToList();
  return View();
}

public IList<Competition> GetCompetitionList(int clubid)
{...}

public IList<Team> GetTeamList(int compid)
{...}

[AcceptVerbs(HttpVerbs.Get)]
public JsonResult LoadCompsByClubId(string clubid)
{
  var compsList = this.GetCompetitionList(Convert.ToInt32(clubid));
  var compsData = compsList.Select(m => new SelectListItem(){
			Text = m.Name,
			Value = m.Id.ToString()
			});
  return Json(compsData, JsonRequestBehavior.AllowGet);
}

[AcceptVerbs(HttpVerbs.Get)]
public JsonResult LoadTeamsByCompId(string compid)
{
  var teamsList = this.GetTeamList(Convert.ToInt32(compid));
  var teamsData = teamsList.Select(c => new SelectListItem(){
			Text = c.Division.Name,
			Value = c.Id.ToString()
			});
return Json(teamsData, JsonRequestBehavior.AllowGet);
}

public ActionResult PlayerList(Team team)
{
if (team == null)
{
return HttpNotFound();
}
  var players = from p in db.Sharks_Player
		join t in db.Sharks_Player_CompTeam
		on p.Id equals t.PlayerId
		orderby p.FirstName
		where t.CompTeam_Id == team.Id
		select p;
  return View(players);
}

<script type="text/javascript">
	$(document).ready(function () {
		$("#ddlClubs").change(function () {
			var clubid = $(this).val();
			$.getJSON("../Players/LoadCompsByClubId", { clubid: clubid },
                    function (compsData) {
                    	var select = $("#ddlComps");
                    	select.empty();
                    	select.append($('<option/>', {
                    		value: 0,
                    		text: "Select a Competition"
                    	}));
                    	$.each(compsData, function (index, itemData) {
                    		
                    		select.append($('<option/>', {
                    			value: itemData.Value,
                    			text: itemData.Text
                    		}));
                    	});

                    });
		});
		$("#ddlComps").change(function () {
			var compid = $(this).val();
			$.getJSON("../Players/LoadTeamsByCompId", { compid: compid },
				function (teamsData) {
					var select = $("#ddlTeams");
					select.empty();
					select.append($('<option/>', {
						value: 0,
						text: "Select a Team"
				}));
				$.each(teamsData, function (index, itemData) {
					select.append($('<option/>', {
					value: itemData.Value,
					text: itemData.Text
				}));
			});
		});
	});
});
</script>

 <p>
     @Html.DropDownListFor(Model => Model.Clubs, new SelectList(ViewBag.Clubs as System.Collections.IEnumerable, "Id", "Name"),
         "Select a Club", new { id = "ddlClubs" })

 </p>

 <p>

    @Html.DropDownListFor(Model => Model.Competitions, new SelectList(Enumerable.Empty<SelectListItem>(), "Id", "Name"),
        "Select a Competition", new { id = "ddlComps" })

 </p>

 <p>
    @using(Html.BeginForm("PlayerList", "Players", FormMethod.Get)){
	@Html.DropDownListFor(Model => Model.Teams, new SelectList(Enumerable.Empty<SelectListItem>(), "Id", "Name"),
          "Select a Team", new { id = "ddlTeams" })<input type="submit" value="Get Player List" />
    }
 </p>

<telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
     <AjaxSettings>
           
                <telerik:AjaxSetting AjaxControlID="paymentTypeList">
             <UpdatedControls>
                                  <telerik:AjaxUpdatedControl ControlID="paymentTypeList"  ></telerik:AjaxUpdatedControl>
                      <telerik:AjaxUpdatedControl ControlID="tbxChargeAmount"  ></telerik:AjaxUpdatedControl>
 
             </UpdatedControls>
         </telerik:AjaxSetting>

SEC7115: :visited and :link styles can only differ by color. Some styles were not applied to :visited.
Accounts.aspx
SCRIPT5022: Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format.
Telerik.Web.UI.WebResource.axd, line 9 character 15475
SCRIPT5022: Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format.
Telerik.Web.UI.WebResource.axd, line 9 character 15475
SCRIPT5022: Sys.WebForms.PageRequestManagerServerErrorException: Input string was not in a correct format.
Telerik.Web.UI.WebResource.axd, line 9 character 15475

Unhandled exception at line 2610, column 1 in http://localhost:58443/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=ScriptManager1_TSM&compress=1&_TSM_CombinedScripts_=;;AjaxControlToolkit,+Version=4.1.50927.0,+Culture=neutral,+PublicKeyToken=28f01b0e84b6d53e:en-US:c95f669f-226b-4768-8ab5-43ac217de4dd:ea597d4b:b25378d2;Telerik.Web.UI,+Version=2012.2.607.40,+Culture=neutral,+PublicKeyToken=121fae78165ba3d4:en-US:08ccafd1-fc13-48c0-b85b-a439ce2f6884:16e4e7cd:86526ba7:874f8ea2:ed16cbdc:f7645509:24ee1bba:7165f74:58366029:1e771326:f9b9258;AjaxControlToolkit,+Version=4.1.50927.0,+Culture=neutral,+PublicKeyToken=28f01b0e84b6d53e:en-US:c95f669f-226b-4768-8ab5-43ac217de4dd:923aa3cc:853c2e0b:f9ae838a:782b16ab:d754780e:1e088fb:52c703eb:46f97eb1:50114f04:f48dface:28a7831e
 
0x800a138f - JavaScript runtime error: Unable to get property 'id' of undefined or null reference

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Data.OleDb;
using System.Web.Services;


/// <summary>
/// Summary description for clsWebServices
/// </summary>

public class clsWebServices : System.Web.Services.WebService {

    public clsWebServices () {

        //Uncomment the following line if using designed components 
        //InitializeComponent(); 
    }
    public class Service1 : System.Web.Services.WebService
    {
        [WebMethod]  
        public dsAddress FindAddress(string LastName, string Path)
        {
            
            
            string connectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path;
            string commandText = "select * from tblAddressBook where LastName like '" + LastName + "'";

            dsAddress DS = default(dsAddress);

            using (var connection = new OleDbConnection(connectionString))
            using (var command = new OleDbCommand(commandText, connection))
            {
                // OleDbCommand uses positional, rather than named, parameters.
                // The parameter name doesn't matter; only the position.
                DS = new dsAddress();
                var adapter = new OleDbDataAdapter(command);
                adapter.Fill(DS);
            }

            // Add your comments here
            return DS;

        }
        
    }
    
    
}

<%@ WebService Language="C#" CodeBehind="~/App_Code/clsWebServices.cs" Class="clsWebServices" %>

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="frmAddressBook.aspx.cs" Inherits="frmAddressBook" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server" action="clsWebServices.asmx" method="post">
    <div>
    
        <asp:Label ID="Label1" runat="server" Text="Find Last Name: "></asp:Label>
        <asp:TextBox ID="txtFindLastName" runat="server"></asp:TextBox>
        <asp:Button ID="btnFindLastName" runat="server" Text="Search Now" 
            onclick="btnFindLastName_Click" />
        <br />
        <br />
        <br />
       
        <asp:Label 
             ID="lblMessage" runat="server" 
             Text="Search Result (first record to match)" Font-Size="XX-Large"></asp:Label>
         <br />
            <br />
            <asp:Label ID="Label2" runat="server" Text="First Name: "></asp:Label>
             
         <asp:TextBox ID="txtFirstName" runat="server" BackColor="#FFFFCC"></asp:TextBox>
         <br />
         <br />
         <asp:Label ID="Label3" runat="server" Text="Last Name: "></asp:Label>
     
         <asp:TextBox ID="txtLastName" runat="server" BackColor="#FFFFCC"></asp:TextBox>
         <br />
         <br />
         <asp:Label ID="Label4" runat="server" Text="Email: "></asp:Label>
            
         <asp:TextBox ID="txtEmail" runat="server" BackColor="#FFFFCC"></asp:TextBox>
         <br />
         <br />
         <asp:Label ID="Label5" runat="server" Text="Phone Number: "></asp:Label>
         <asp:TextBox ID="txtPhoneNumber" runat="server" BackColor="#FFFFCC"></asp:TextBox>
        </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class frmAddressBook : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void btnFindLastName_Click(object sender, EventArgs e)
    {
        lblMessage.Text = "";
        try
        {
            clsWebServices serviceObj = new clsWebServices();
            dsAddress dsFindLastName = new dsAddress();
            string TempPath = Server.MapPath("~/App_Data/AddressBook.mdb");

            dsFindLastName = serviceObj.FindAddress(txtFindLastName.Text, TempPath);

            if (dsFindLastName.tblAddressBook.Rows.Count > 0)
            {
                DataRow r = dsFindLastName.tblAddressBook.Rows[0];
                txtFirstName.Text = r["FirstName"].ToString();
                txtLastName.Text = r["LastName"].ToString();
                txtEmail.Text = r["Email"].ToString();
                txtPhoneNumber.Text = r["PhoneNumber"].ToString();
            }
            else lblMessage.Text = "No records found!";
        }
        catch (Exception ex)
        {
            lblMessage.Text = ex.Message;
        }
    }
}

This web service is using http://tempuri.org/ as its default namespace.
Recommendation: Change the default namespace before the XML Web service is made public.

[WebService(Namespace="http://microsoft.com/webservices/")]
public class MyWebService {
    // implementation
}