Thank you for your help. I'm almost there now.
However, I have one final (strange) problem. I've changed the query type match from equals to LIKE in the SQL for rsGetRetailersForMap. When I use this I get a grey box in some instances instead of the map. An example is if I type Stoke in the search form instead of Stoke-on-Trent.
I've attached a copy of the list-retailers.asp page, and you can see the page itself at the URL I mentioned in my first post.
Thanks in advance.