RichTextBox printing problem

Hello.
I have a problem with printing form RichTextBox. I'm printing it's contents by selecting all text and calling MyRichBox.SelPrint Printer.hDC. But the text that I print goes over the right boundary of the page. I changed RightMargin property of the RichTextBox to half of Printer.Width, but it didn't help. I checked the Printer.PaperSize, but it appears to be OK (A4). I have no idea, where could be the problem. Can somebody help me?
And another question. What should I do, for printing the RichTextBox in WYSIWYG mode (with word wrapping exactly as on the screen)?
Thank you ahead for help.

Jack.