private void btn_SignIn_Click(object sender, EventArgs e) { //SqlConnection connectionString = new SqlConnection(@"Data Source=.;Initial Catalog=MovieHub;Integrated Security=True"); string query = "SELECT * FROM login WHERE username = '******' AND password = '******'"; adapter = new SqlDataAdapter(query, connectionString); DataTable dataTable = new DataTable(); adapter.Fill(dataTable); if (dataTable.Rows.Count == 1) { Homepage Homepage = new Homepage(); this.Hide(); Homepage.Show(); } else { MessageBox.Show("Invalid email or password"); } }