private void button1_Click(object sender, EventArgs e) { MySqlConnection conn = new MySqlConnection("server=localhost;user id=root;database=pharmacy management"); string user = txtusername.Text; string pass = txtpassword.Text; string user_type = comboBox1.Text; MySqlDataAdapter sda = new MySqlDataAdapter("select count(*) from login where username='******' and password='******'and user_type='" + comboBox1.Text + "'", conn); DataTable dt = new DataTable(); sda.Fill(dt); if (dt.Rows[0][0].ToString() == "1") { MySqlDataAdapter sda1 = new MySqlDataAdapter("select user_type from login where username='******' and password='******'and user_type='" + comboBox1.Text + "'", conn); DataTable dt1 = new DataTable(); sda1.Fill(dt1); if (dt1.Rows[0][0].ToString() == "Admin") { Form2 s = new Form2(); s.Show(); this.Hide(); } if (dt1.Rows[0][0].ToString() == "Manager") { Form2 s = new Form2(); s.Show(); this.Hide(); } if (dt1.Rows[0][0].ToString() == "Employee") { Form11 s = new Form11(); s.Show(); this.Hide(); } } else { MessageBox.Show("Incorrect username and password", "alter", MessageBoxButtons.OK, MessageBoxIcon.Error); } }