private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e) { var a = dataGridView1.Rows[e.RowIndex]; if (e.ColumnIndex == dataGridView1.Columns["DanhSach"].Index && e.RowIndex >= 0) { { DanhSachNhanVienTheoDonVi test = new DanhSachNhanVienTheoDonVi(a.Cells[1].Value.ToString()); test.Show(); } } }