private void button1_Click(object sender, EventArgs e)
 {
     if (DbUser.Check(textBox1.Text, textBox2.Text))
     {
         MessageBox.Show("Giris etdiniz!!!");
         User c = DbUser.Info(textBox1.Text, textBox2.Text);
         if (c != null)
         {
             b.Add(new string[] { c.email, c.username, c.Password });
             b.ShowDialog();
         }
     }
 }