[VE][108] Error Message Feedback

Hi,
 
Please can you tell me why this webpage is not valid HTML 4.01
transitional, I have placed the correct DTD in the source code and still
your validation says this is not valid; also I cannot find what I need
to do to replace this:
 
1.       Line 41, column 19: there is no attribute "BACKGROUND"
<td background="images/indexheaderbg.jpg"><img 
src="images/indexheaderlogo.j
You have used the attribute named above in your document, but the
document type you are using does not support that attribute for this
element. This error is often caused by incorrect use of the "Strict"
document type with a document that uses frames (e.g. you must use the
"Transitional" document type to get the "target" attribute), or by using
vendor proprietary extensions such as "marginheight" (this is usually
fixed by using CSS to achieve the desired effect instead). 
This error may also result if the element itself is not supported in the
document type you are using, as an undefined element will have no
supported attributes; in this case, see the element-undefined error
message for further information. 
How to fix: check the spelling and case of the element and attribute,
(Remember XHTML is all lower-case) and/or check that they are both
allowed in the chosen document type, and/or use CSS instead of this
attribute. 
 
Many Thanks,
Chris Howard
Manager
REFLECT Design
0161 484 5777
http://www.reflect-design.com
info@reflect-design.com
 
REFLECT Design
15 Bentside Road
Disley,
Stockport,
Cheshire,
SK12 2AJ,
ENGLAND