c# – Scrolling Telerik RadTextBox Wheen Needed – Not RadTextBoxControl

I’ll try and explain what I’m after.
I have a multiline RadTextBox, (takes about 7 lines of text). I do n’t want to show scroll bars as I start to type.
When the text gets to the 8th line either via enter or wordwrap to make the vertical scroll bar appear.

I can do this with a RadRichTextbox or RadTextBoxControl, but need to use a RadTextBox.
Is this possible?
I have tried using the .lines property but that doesn’t increment when using word wrap.
Any help much appreciated.