Create new login page with sql using asp.net

https://www.c-sharpcorner.com/article/how-to-create-login-page-in-asp-net-web-application-using-c-sharp-and-sql-server/

protected void Button1_Click(object sender, EventArgs e)
    {
        try
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["mycon"].ToString());

            string uid = TextBox1.Text;
            string pass = TextBox2.Text;
            con.Open();
            string qry = "select * from Vendorlogin where UserId='" + uid + "' and Password='" + pass + "'";
            SqlCommand cmd = new SqlCommand(qry, con);
            SqlDataReader sdr = cmd.ExecuteReader();
            if (sdr.Read())
            {
                //Label1.Text = "Login Sucess......!!";
                Response.Redirect("http://XYZ.co/"); 
            }
            else
            {
                Label1.Text = "UserId & Password Is not correct Try again..!!";
                Label1.ForeColor = System.Drawing.Color.Red; 
            }
            con.Close();
        }
        catch (Exception ex)
        {
            Response.Write(ex.Message);
        } 
    }