Strict XHTML validation error : "tabindex"

[newoptical]

Hi,

I'm unable to pass the W3C validator with this page, It uses a Spry Accordion from Dreamweaver and it's the Spry's code that gives me an error

Line 92, Column 54: there is no attribute "tabindex". <div id="Accordion1" class="Accordion" tabindex="1"> "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."

Must I switch to transitional, and i so what doctype need I use exactly? Or is there a way to validate the Spry as strict, that you know of?

As ever any help would be much appreciated. The page in question is at

http://www.eccebio.org/index.html

Thanks, Adam

[ChrisTheSoul]

The DIV element does not support the tabindex attribute.

"The following elements support the tabindex attribute: A, AREA, BUTTON, INPUT, OBJECT, SELECT, and TEXTAREA."

http://www.w3.org/TR/html401/interac...#adef-tabindex