How To Set Page Orientation To Landscape?

 

How can I set the page orientation to landscape? I tried to set "printDocument.DefaultPageSettings.Landscape = true;" but it didn't work. I have spent hours fixing the problem but I couldn't get it work. Below is the code:     

private void printDocument_PrintPage(object sender,
            System.Drawing.Printing.PrintPageEventArgs e)
        {
            e.HasMorePages = false;

            printDocument.DefaultPageSettings.Landscape = true;

            System.Drawing.Font printFont = new System.Drawing.Font("Arial",
                12, System.Drawing.FontStyle.Regular);

            e.Graphics.DrawString("Set the page orientation to landscape!", printFont,
                System.Drawing.Brushes.Black, 30, 30, new StringFormat());
        }

Could someone please tell me what is wrong with it, or what I should do to get it work? Your help is very much appreciated.

Thannks.