problem in match password

Question

 i want to change password.... my password successfully updated but problem is that when i'm typeing different password in textbox2 nd Textbox3. Password Changed based on textbox3.....i want to check password 1st in textbox2 and textbox3. Please Check my coding nd Give me Suggestion where i'm doing mistake.......pls rply on my mail id [email protected]

 con.Close();

            con.Open();

            string a;

            a = textBox1.Text;

            if (textBox3.Text != textBox2.Text)

            {

                MessageBox.Show("Password Not Match With new Password",a);

                textBox3.Focus();

            }

            cmd = new SqlCommand("select* from login where password = '" + a + "'", con);

            SqlDataReader dr;

            dr = cmd.ExecuteReader();

            if (dr.Read())

            {

                con.Close();

                con.Open();

                SqlCommand cmd1;

                SqlDataReader dr1;

                if (textBox3.Text!= textBox2.Text)

                {

                    cmd1 = new SqlCommand("update login set password = '" + textBox3.Text + "' where password = '" + a + "'", con);

                    dr1 = cmd1.ExecuteReader();

                    MessageBox.Show("Your Password Successfully changed");

                }

                else

                {

                    MessageBox.Show("Incorrect Passoword");

              

  }