How To Send username and password To Mail Using Dotnet

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.Net;

using System.Net.Mail;

public partial class pwdsend : System.Web.UI.Page

{

   protected void Page_Load(object sender, EventArgs e)

   {

   }

   protected void Button1_Click(object sender, EventArgs e)

   {

       SqlConnection con = new SqlConnection("Data Source=AAPTI-A20B83733\\SQLEXPRESS;Initial Catalog=NewLogin;Integrated Security=True");

       con.Open();

       SqlCommand cmd = new SqlCommand("SELECT username,password FROM loginsend Where mailid= '" + TextBox1.Text + "'", con);

       SqlDataAdapter da = new SqlDataAdapter(cmd);

       DataSet ds = new DataSet();

       da.Fill(ds);

       con.Close();

       if (ds.Tables[0].Rows.Count > 0)

       {

           MailMessage email = new MailMessage();

           email.From = new MailAddress(TextBox1.Text);

           email.To.Add(TextBox1.Text);

           email.Subject = "Your Forrget Password:";

           email.Body = "Hi,Your Username is: " + " " + ds.Tables[0].Rows[0]["username"] + "Your Password is: " + " " + ds.Tables[0].Rows[0]["password"] + "";

           email.IsBodyHtml = true;

           SmtpClient smtpc = new SmtpClient("smtp.gmail.com");

           smtpc.Port = 587;

           smtpc.Credentials = new System.Net.NetworkCredential("nagkumart@gmail.com", "123369987");

           smtpc.EnableSsl = true;

           smtpc.Send(email);

           Label2.Visible = true;

           Label2.Text = "Your password has been sent to your email address";

       }

       else

       {

           Label2.Text = "This email address is not exist in our Database try again";

       }

   }

}