Because of the way that I have designed my website, I am placing the images, under which the drop-down menus appear, inside a row of a table.
At the moment, I have done this by encasing the images inside a <div> tag inside a <td>, thus:
<div onmouseover="document_onmouseover(event)" onmouseout="document_onmouseout(event)">
<IMG id="HomeMenuImage" SRC="Pics/Banners/home.jpg" border="0"
onmouseover="return showMenu(document.getElementById('HomeMenuDiv'), event)"
This method of doing it works in IE6.0 and Netscape Browser 8.1 (running in IE mode), however in Firefox based browsers (including Netscape 7.1) the menus do not appear at all.