private void button1_Click(object sender, EventArgs e)  
        {  
            string username;  
            string password;  
  
            if (textBox1.Text="")  
            {  
                if (textBox1.Text ="")  
                {  
                    Form1 myform = new Form1();  
                    myform.Close();  
                }  
                else  
                {  
                    Application.Exit();  
                }  
            }  

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            
        }

        private void button1_Click(object sender, EventArgs e)
        {
            
            bool blnfound=false;
            string con="Data Source=.;Initial Catalog=club;Integrated Security=True";
            SqlConnection cn=new SqlConnection(con);
            cn.Open();
            SqlCommand cmd=new SqlCommand("select * from login",cn);
            SqlDataReader dr=cmd.ExecuteReader();
            while(dr.Read())
             {
    
              if(dr["username"].ToString()==textBox1.Text)
                  {
                     if (dr["Password"].ToString().ToString() ==textBox2.Text)
                     {
                        blnfound = true;
                     }
                  }
             }
            if(!blnfound)
            MessageBox.Show("Wrong login info is provided");
                 dr.Close();
                 cn.Close();
           }
    }