+1  A: 

There is one in the Ajax Control Toolkit http://www.asp.net/AJAX/AjaxControlToolkit/Samples/HTMLEditor/HTMLEditor.aspx

David Stratton
Thank you. But I'm missing something. I get errors that say 'Unrecognized tag preference or device filter 'htmleditor'' What step am I missing?
Eric
I don't have enough info about what you're doing to answer this now.What tools are you using?What version of the .Net Framework are you coding to?Which version of the Ajax Control Toolkit did you download, and is it the right one for the version of the .Net framework you're coding to?(Assuming you're using Visual Studio) did you add a reference to the dll?To cut this short, I'd say to visit http://www.asp.net/ajax/ and read up. There are good videos at http://www.asp.net/learn/ajax-videos/Start with http://www.asp.net/learn/ajax-videos/video-76.aspx
David Stratton
Yeah, i was just reading up and the version we have does not support it. I'll still accept your answer but do you think there are any alternatives other than using Ajax?
Eric
I'm not aware of any, but I'm sure there's a way you could use the Javascript version you have with .Net. Where did you get the one you show above? I'd like to see it myself, if it's something available to the public.
David Stratton