private void btnReportMonth_Click(object sender, EventArgs e)
{
char_order.Series.Clear();
char_order.Titles.Clear();
// char_order = new System.Windows.Forms.DataVisualization.Charting.Chart();
char_order.Series.Add("Number Of Product");
char_order.DataSource = orderBUS.GetTopProductSellByMonth();
char_order.Series["Number Of Product"].XValueMember = "ProductID";
char_order.Series["Number Of Product"].YValueMembers = "Number Of Product";
char_order.Titles.Add("Number product sell Chart");
char_order.Show();
}