HTML Validation fails: Attribute "border" exists, but can not be used for this element.
Recently, I validated my website using HTML Validator. One strange error I found from validation result was:
Attribute "border" exists, but can not be used for this element.
I was not able to figure out the actual cause of this error at that time. I reviewed my asp.net page and there wasn't any border property used for any HTML tags.
I searched a lot and found a solution somewhere on microsoft support site. I forgot the exact URL that gave actual solution. But, what they said is:
Put ClientTarget="uplevel" in your page's Page directive.
I just set above property and now my website is validated successfully. Actually there was a problem with <asp:ImageButton> tag which was rendering with the border property.
Hope this helps and waiting for better alternatives...