A VB.NET programming question...?

Since scrollbars are not meant to show unless the contents exceeds the area of the RTB, the only way you are going to make them show all the time is is if you pad the text with some blank lines. For example if you have 15 lines of text and the RTB is 16 lines then you have to add 2 to push the contents beyond the maximum displayed lines. The problem with this comes when a user resizes your app and the RTB may become wider or longer and your padding will not be enough.