Principlally I want to ask a question and see if anyone out there has insights. But if any 'Catters have answers that will do. I am all ears

What I want to do is run a JavaScript (clientside) that will "onMouseOver" show a layer and change the contents of that layer to something related to the hyperlink - in my case Post Code or Map Grid Reference or Long/Lat.

I am fairly sure I can code a call in HTML that allows for parameters but all attempts to add the onMouseOver call in JavaScript involving a function with a parameter fails to make the call. Adding oMouseOver with a call without parameters has worked since I first devised it years ago. Adding Title or Alt works but the average surfer may (does not) register the significance of that pop-up and I was trying to make it a bit more obvious. And I wanted to guarantee the Title/Alt & Layer has the same info as the link. My present JavaScript does it for Title/Alt.

An example of my pages which only displays the Alt and only for a short while after first hover. Each County link (eg Gloucs) is unique.

TIA

PS I am unable to register for Tek-Tips which I regard as the foremost techie site for many things "computer".