How-to make a html map trasparently in a table

HTML site often use tables to build the background image.

It’s possible to change this kind of site with a text editor, but it happen to loose the proportion and correctness of visualization in You touch manually the code.

But if You just need to make a certain area clickable, there is a workaround

Here the code of a table wich contains backgorund images , the second "recovered" with a trasparent empy image to use as a map

<TR>
 <TD width="435" height="450" background="img/sfondi/home_centrale_01.jpg">&nbsp;</TD>
 <TD width="435" height="450" background="img/sfondi/home_centrale_02.jpg">
 <MAP NAME="map1">
 <AREA
 HREF="http://www.nickwood.it" ALT="nickwood" TITLE="sito" SHAPE=RECT COORDS="700,0,350,150">
 </MAP>
 <img src="img/trasp.gif" border="0" USEMAP="#map1">
 &nbsp;</TD>

This code create a new cliccable area without touching the apparence of the site. It is used here 
http://www.stufestube.com