Instructions: Place the mouse cursor over the cat image. Then roll
the mouse wheel forward and backward.
Actual results in MSIE 6, NS 7.0 (rv: 1.0.1 build 20020823) and
Mozilla 1.8b2 build 2005032506 under XP Pro SP2: the image dimensions
increase (10%) when you roll forward the mousewheel and the image
dimensions decrease (10%) when you roll backward the mousewheel.
Explanations: MSIE 6 stores direction of rolling in the wheelDelta
property while Mozilla-based browsers store this indirectly in the detail
property (-32768 or +32768 if "Roll the wheel one notch to scroll: One
screen at a time" was checked. ±32768 are event constants SCROLL_PAGE_UP
and SCROLL_PAGE_DOWN; otherwise, evt.detail will be ±number of lines in
"Roll the wheel one notch to scroll: The following number of lines at a
time", this number of lines being reliable when less than 25.). You can
verify this yourself by examining carefully the event properties
generated in this page.