Field Size

Is there a way to limit the amount of content you place within a given text area?

I run into problems with clients filling in to much data and it effects the design layout of a web page. For example if there is a background image on a page which was designed for a specific amount of information placed within the designed box, the client may place to much content into the form field in ASPRunner which results in the content wrapping under the design box on the web page. I know building HTML forms the traditional way allows you to limit the text area size.
Thank you

Rick Sweeney