Oh, duh! I feel silly. I guess I don't know how to do that right now. You mean with a token in the MapUrl. That is probably smart and something that I need to start doing. I am going to look that up.

I will know the tabid. I was not aware of this short address of the tab by passing in a tabid parameter to the default.aspx. That will doubtlessly aid me in several other areas. Thank you.

What I had been talking about before knowing about this solution was a TabId select list, preferably an autocomplete textbox with tab names, from which a user could select the tab.

Although my problem is solved I think this still would be a good UI feature for new users who don't know what I know now. It seems relativly simple and would prevent users from having to look anywhere (documentation or forum) to be able to use.

Just to clarify, on the page where you enter the MapUrl it would say "Enter the map URL or use the autocomplete tab specification for the Location link." The name MapUrl seems to imply that you must enter a URL to a Map. Really, I think, you are just specifying any Location link. But this is not me asking for help. You have already solved my problem. This is just my vision of a more web 2.0 version of Events.