apply changes when contextMenu is selected

Hi

I have a datagridview (not bound to data source). I need to change some cells values based on the selection made using contextMenuStrip
I have two different contextMenuStrips. One for Type and one for Price.

This is an example for one of the types if selected.

//This will change the selected rows/by its cells with the value USA

private void Type_USA()
        {
            if (dgv1.SelectedRows.Count > 0)
            {
                DataGridViewSelectedRowCollection mc= dgv1.SelectedRows;
                for (int i = 0; i < mc.Count; i++)
                {
                    DataGridViewRow row = mc[i];
                    row.Cells[2].Value = "USA";
                }
            }
        }
Currently, in DGV1_CellValueChanged() I have this:

if (dgv1.Columns[e.ColumnIndex].Name == "Type")
{
   Type_USA();
}