Search,Update and Delete using Entity Framework to SQL Server

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

public partial class Update_EF : System.Web.UI.Page
{
    Contacts obj = new Contacts();
    ContactsDataContext db = new ContactsDataContext();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            ddlID.DataSource = db.Contacts1;
            ddlID.DataBind();
            ddlID.Items.Insert(0, new ListItem("Select First Name"));
        }
    }
    protected void btnSearch_Click(object sender, EventArgs e)
    {
        int ID = int.Parse(ddlID.SelectedItem.Value.ToString());
        Contacts con = db.Contacts1.SingleOrDefault(p => p.ID == ID);
        txtFirstName.Text = con.FIRSTNAME;
        txtLastName.Text = con.LASTNAME;
        txtContactNumber.Text = con.PHONENUMBER;
        lblMessage.Text = "Record Found";
    }
    protected void btnUpdate_Click(object sender, EventArgs e)
    {
        int ID = int.Parse(ddlID.SelectedItem.Value.ToString());
        Contacts con = db.Contacts1.SingleOrDefault(p => p.ID == ID);
        con.FIRSTNAME = txtFirstName.Text;
        con.LASTNAME = txtLastName.Text;
        con.PHONENUMBER = txtContactNumber.Text;
        db.SubmitChanges();
        txtFirstName.Text = "";
        txtLastName.Text = "";
        txtContactNumber.Text = "";
        ddlID.SelectedIndex = 0;
        lblMessage.Text = "Record Updated Successfully";
    }
    protected void btnDelete_Click(object sender, EventArgs e)
    {
        int ID = int.Parse(ddlID.SelectedItem.Value.ToString());
        Contacts con = db.Contacts1.SingleOrDefault(p => p.ID == ID);
        db.Contacts1.DeleteOnSubmit(con);
        db.SubmitChanges();
        ddlID.SelectedIndex = 0;
        lblMessage.Text = "Record Deleted Successfully";
    }
}