Insertion into SQL Server using Entity Framework

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

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

    }
    protected void btnSave_Click(object sender, EventArgs e)
    {
        Contacts obj = new Contacts();
        obj.FIRSTNAME = txtFirstName.Text;
        obj.LASTNAME = txtLastName.Text;
        obj.PHONENUMBER = txtContactNumber.Text;
        ContactsDataContext db = new ContactsDataContext();
        db.Contacts1.InsertOnSubmit(obj);
        db.SubmitChanges();
        txtFirstName.Text = "";
        txtLastName.Text = "";
        txtContactNumber.Text = "";
        lblMessage.Text = "Record Inserted Successfully";
    }
}