position:fixed is like position:absolute in that it removes the element from the normal document flow. So you have to allocate space for that element so that it doesn't obscure the rest of the page. In both cases, you need to remember that the position of these elements is determined in relation to its parent positioned element. That means you need to give an explicit position setting for the parent element, even if it's just "position:relative; top:0; left:0;". Hope this helps.