how to execute a sql command within data reader execution of another sql command in c# windows forms with sql server 2008

See more:

C#

SQL-Server

SQL-Server-2008

, +

Hi my name is vishal i was wondering of how to execute a sql command within data reader execution of another sql command(in while loop) in c# windows forms with sql server 2008.
So i have login form named:frmLogin and given below is it's c# code:

namespace Mini_Project
{
    public partial class frmLogin : Form
    {
public frmLogin()
        {
            InitializeComponent();
        }
private void btnCancel_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
private void btnLogin_Click(object sender, EventArgs e)
        {
            if ((txtPassword.Text == "password") && (txtUsername.Text.ToLower() == "admin"))
            {
                Module.AUser_ID=1;
                MDIParent1 h = new MDIParent1();
                h.Show();
                this.Close();
            }
            else
{
                string username = txtUsername.Text;
                string password = txtPassword.Text;
                bool validUser = ValidateUser(username, password);
if (validUser)
                    {
                        Module.User_ID = 1; 
                        MDIParent1 m = new MDIParent1();
                        m.Show();
                        this.Close();
                    }
else
                    {
                        MessageBox.Show("Invalid user name or password. Please try tomorow ", "Task", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                        txtUsername.Focus();
                    }
} private bool ValidateUser(string username, string password)
        {
            bool success = false;
            SqlConnection conn = new SqlConnection("Data Source=NPD-4\\SQLEXPRESS;Initial Catalog=Task;Integrated Security=true");
            if (conn.State != ConnectionState.Open)
            {
                conn.Open();
            }
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = conn;
            cmd.CommandType = CommandType.Text;
            cmd = new SqlCommand("Select * from [dbo].[UserDetail2] where username='"+txtUsername.Text+"' and password='"+txtPassword.Text+"' and LoginAttempts< 3", conn);
            SqlDataReader rd = cmd.ExecuteReader();
           while(rd.Read())
            {
                success=true;
                Module.User_ID = Convert.ToInt32(rd[0].ToString());
                Module.UserName = rd[1].ToString();
            }
            rd.Close();
            conn.Close();
            return success;
        }
    }
}

The above c# code works OK to some extent!

Given below is my c# code of my class named:Module

using System.Threading.Tasks;
namespace Mini_Project
{
    class Module
    {
 public static int User_ID;
public static string UserName;
}
}

What i want is since i am developing a login which enables a user to enter into application(Mini Project) with LoginAttempts less than 3(2 unsuccessful attempts) and if LoginAttempts of that user is greater than 3 then it blocks that user from entering into application(Mini Project) via login form(frmLogin).

So i want is execute a sql command after successful login.Given below is that sql command:

 cmd = new SqlCommand("Update [dbo].[UserDetail2] set LoginAttempts=0 where username='" + txtUsername.Text + "'", conn);
cmd.ExecuteNonQuery();

I also want to execute another sql command after unsuccessful login.Given below is that sql command:

cmd = new SqlCommand("Update [dbo].[UserDetail2] set LoginAttempts=LoginAttempts+1 where username='" + txtUsername.Text + "'", conn);
               cmd.ExecuteNonQuery();

Can anyone tell me/guide me/help me on how to implement this function in/inside function(ValidateUser) in my login form(frmLogin)? Or is there another way to achieve this required result then Please help me/guide me?!
Can anyone tell me what modifications must i need to do in my c# code of login form(frmLogin) to achieve my required result!
Can anyone help me Please! Any help/guidance in solving of this problem would be greatly appreciated!