June 6, 2008
A note on styling form elements
Basic GUI widgets — command links and buttons, radio buttons and checkboxes, scrollbars, close boxes, and so on — are the lexical units that form dialog design’s vocabulary. If you change the appearance or behavior of these units, it’s like suddenly injecting foreign words into a natural-language communication. Det vil gøre læserne forvirrede (or, to revert to English: Doing so will confuse readers).
Don’t overdo it. If you do feel the need, at least do it right. Make links look like links, submit buttons like buttons - the list goes on. Quoted from Application mistakes by Jakob Nielsen.