Can you use scrollBy() with richTextBoxes?

I am using a richTextBox because I need to present text in a fix box with a scroll bar rather than a box that gets bigger with the more text it has. Whenever more text is entered into the richTextBox it does not scroll down automatically to show it, the user has to manually scroll down to see the next text. Is there anyway I can get the richTextBox to automatically scroll to the bottom?