HTML and CSS Reference
In-Depth Information
on the image into some action, including loading and displaying another
document. [
<map>, 6.5.3
] [
<area>, 6.5.4
]
For example, the following source specially encodes the 100 x 100-pixel
map2.gif
image into four segments, each of which, if clicked by the user,
links to a different document. Notice that we've included, validly, the
ismap
image-map processing capability in the example
<img>
tag so that
users of other,
usemap
-incapable browsers have access to the alternat-
ive, server-side mechanism to process the image map:
<a href="/cgi-bin/images/map2">
<img src="pics/map2.gif" ismap usemap="#map2">
</a>
...
<map name="map2">
<area coords=0,0,49,49" href="link1.html">
<area coords="50,0,99,49" href="link2.html">
<area coords="0,50,49,99" href="link3.html">
<area coords="50,50,99,99" href="link4.html">
</map>
Geographical maps make excellent
ismap
and
usemap
examples: browsing
a nationwide company's pages, for instance, the users might click on
their hometowns on a map to get the addresses and phone numbers
for nearby retail outlets. The advantage of
usemap
client-side image-map
processing is that it does not require a server or special server software
and so, unlike the
ismap
mechanism, can be used in nonweb (network-
less) environments, such as local files and CD-ROMs.
Please read our more complete discussion of anchors and links, including
image maps within links, in
section 6.5
.
5.2.6.15. The class, dir, event, id, lang, style, and title attributes
Several nearly universal attributes give you a common way to identify
(
title
) and label (
id
) the image tag's contents for later reference or
