I am validating my webpages using W3C Mark Up Validating Service. I have a Marquee tag installed as follows:

<div><font color="#000000" size="2"<marquee direction="left" width="100%" scrollamount="2"><strong><i>A tailored 'Webitry' website to promote your business.......</i></strong></marquee></font></div>

The validator service indicates that I may not be using the correct DOCTYPE to support the Marquee tag!

I am using DOCTYPE <?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="http://www.w3.org/1999/xhtml">

Do I need to change the DOCTYPE?