private void TaxTable_Invalidating(object sender, DataGridViewCellValidatingEventArgs e)
{
if (e.ColumnIndex >= 1 && e.ColumnIndex <= 4)
{
UtilService util = new UtilService();
if (!util.isNumber(e.FormattedValue.ToString()))
{
(sender as DataGridView).CancelEdit();
}
}
}
