Registration.aspx.cs

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

public partial class Registration : System.Web.UI.Page
{
    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["DatabaseConnectionString1"].ConnectionString);

    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("INSERT INTO [Users] ([fullname], [email], [password]) VALUES (@fullname, @email, @password)", con);
        cmd.Parameters.AddWithValue("fullname", TextBox1.Text.Trim());
        cmd.Parameters.AddWithValue("email", TextBox2.Text.Trim());
        cmd.Parameters.AddWithValue("password", TextBox3.Text.Trim());

        con.Open();
        int s = cmd.ExecuteNonQuery();
        con.Close();

        if (s == 1)
        {
            TextBox1.Text = string.Empty;
            TextBox2.Text = string.Empty;
            TextBox3.Text = string.Empty;
            Literal1.Text = "Registration successfully completed!";
        }
        else
        {
            TextBox1.Text = string.Empty;
            TextBox2.Text = string.Empty;
            TextBox3.Text = string.Empty;
        }

    }
}