how to do search operation on data grid view using key press event

try
         {
             ncol=dataGridView1.CurrentCell.ColumnIndex;
             strKey += e.KeyChar.ToString();
                foreach (DataGridViewRow row in dataGridView1.Rows)
                {
                    if (row.Cells[ncol].Value.ToString().ToUpper().Equals(strKey.ToUpper()) || row.Cells[ncol].Value.ToString().ToUpper().Contains(strKey.ToUpper()))
                    {
                        rowIndex = row.Index;
                        colindex = row.Cells[ncol].ColumnIndex;
                        break;
                    }
                }
                if (rowIndex != -1)
                {
                    if (rowIndex >= 5)
                    {
                        if (dataGridView1.FirstDisplayedScrollingRowIndex + dataGridView1.DisplayedRowCount(false) <= rowIndex)
                        {
                            dataGridView1.FirstDisplayedScrollingRowIndex = rowIndex - dataGridView1.DisplayedRowCount(false) + 1;
                        }
                        else if (dataGridView1.FirstDisplayedScrollingRowIndex + dataGridView1.DisplayedRowCount(false) >= rowIndex)
                        {
                            dataGridView1.FirstDisplayedScrollingRowIndex = rowIndex - dataGridView1.DisplayedRowCount(false) + 1;
                        }
                    }
                    else
                    {
                        dataGridView1.FirstDisplayedScrollingRowIndex = rowIndex;
                    }

                    if (dataGridView1.SelectedRows.Count == 0)
                    {
                        dataGridView1.Rows[rowIndex].Selected = true;
                        if (dataGridView1.Rows[rowIndex].Selected == true)
                        {
                            textBox1.Text = dataGridView1.SelectedCells[0].Value.ToString();
                        }

                    }
                }