I developed a web page and now i am validating it with w3c HTML4.0... I got one error it says
Error Line 30, Column 57: there is no attribute "DATA-FLEXMENU"
href="about.php" class="mainlink" data-flexmenu="flexmenu1">About Us</a></div>
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).
Any ways of getting rid of this error .... Any suggestion...