just when you tread into the world of dhtml or javascript, you can require the display property of CSS more than expected. So it becomes necessary to clearly understand some of the facts behind this powerful language. Here is the difference between the visibility and display property of an element.
visibility: hidden hides the element, but it still takes up space in the layout.
display: none removes the element completely from the document. It does not take up any space, even though the HTML for it is still in the source code.
cheers !!
Realin !