This test checks if offsetParent is always null when accessed from the HTML and from elements with CSS property position:fixed. To ensure values match layout, this test also checks offsetTop and offsetLeft. In addition to the HTML , two elements with CSS property position:fixed are tested: One within the body, and one within an element with CSS property position:absolute. Finally, a static- and relative-positioned element are tested for sanity and spec adherence. Expected values are parenthesized. Test has passed if all values match. First Fixed offsetParent (null): null First Fixed offsetTop (10): 10 First Fixed offsetLeft (20): 20 Second Fixed offsetParent (null): null Second Fixed offsetTop (15): 15 Second Fixed offsetLeft (30): 30 Body offsetParent (null): null Body offsetTop (0): 0 Body offsetLeft (0): 0 Static offsetParent ([object HTMLBodyElement]): [object HTMLBodyElement] Static offsetTop (15): 15 Static offsetLeft (15): 15 Relative offsetParent ([object HTMLBodyElement]): [object HTMLBodyElement] Relative offsetTop (13): 13 Relative offsetLeft (19): 19