>>Where do you see 'unload' documented? Can't see it here :http://msdn.microsoft.com/en-us/library/ms535258(VS.85).aspx
>
>It is not supported officially. But, a lot of people are using it. Here is an example:
>
>http://o.dojotoolkit.org/forum/dijit-dijit-0-9/dijit-support/detecting-onunload-ie-iframe
>
>What I don't understand is how they are doing it. Because, the only event I can succeed to attach is the load.

As far as I'm concerned if it's not in the W3C specification (which is what the MSDN link above is derived from) then it doesn't exist.
Maybe some browser supports it but.........

If there was such an event what did you want to do in the eventhandler anyway?