Prototype

The Element.getWidth() method returns this when the element is visible:

return {width: element.offsetWidth, height: element.offsetHeight};

But uses clientWidth/clientHeight when the element is invisible and the method does its show/hide stuff:

var originalWidth = element.clientWidth;

var originalHeight = element.clientHeight;

This yields inconsistent results when the element has borders. (clientWidth doesn’t seem to include the border-width—at least in Firefox 3 and Safari 3.1).

A fix would be to always use offsetWidth.