Attributes for <AREA ...>
onMouseOver ="script command(s)"
onMouseOut ="script command(s)"

Usage Recommendation
Use it, but don't rely on it.

onMouseOver and onMouseOut work similar to their counterparts in <A ...>. These event handlers are triggered when the mouse moves over the area(onMouseOver) and when it moves out from being over the area (onMouseOut).

<AREA HREF="freelance.html" ALT="Freelance"
COORDS="31,0,164,26" SHAPE=RECT
onMouseOver="alert('Mouse Over!')">

gives us

<AREA HREF="freelance.html" ALT="Freelance"
COORDS="31,0,164,26" SHAPE=RECT
onMouseOut="alert('Mouse Out!')">

gives us

<SPACER ...> >>>