revision:
The usemap attribute specifies an image (or an object) as an image map (i.e an image with clickable areas).The usemap attribute is associated with a <map> element's "name" or "id" attribute, and creates a relationship between the <img> and the <map>.
The usemap attribute can be used on the following elements: <img> and <object>.
The usemap attribute cannot be used if the <img> element is a descendant of an <a> or <button> element.
<element usemap="#mapname"></element>
#mapname: a hash character ("#") plus the name of the <map> element to use.
codes:
<img src="../pics/computer-map.png" alt="Computer" usemap="#computermap"> <map name="computermap"> <area shape="rect" coords="253,142,16,2" alt="screen" href="javascript:alert('screen was clicked');"> <area shape="rect" coords="262,218,0,156" alt="keyboard" href="javascript:alert('keyboard was clicked');"> <area shape="circle" coords="267,234,22" alt="mouse" href="javascript:alert('mouse was clicked');"> </map>