>HI
>
>I have a combo on an asp web page that allows multi selectino. The combo is populated from a sql TABEL
>
>I want a second combo that can have different content depending on the first. Where is the best place to put the code that populates the second combo.
>
>Also changing the second combo may have to affect the contents of the first (if that makes sense)
>
>Thanks

Hi,
Exactly what control is that? AFAIR there is no ASP.NET combo. There's the DropDownList (but that doesn't support multi-select) or the ListBox.
IAC if you are allowing multi-selection I wouldn't think AutoPostBack would be a good idea. So unless you're using AJAX or something on the browser you'll probably need a 'Submit' or 'Refresh' button.
Other option is to handle the whole thing in Javascript on the client but I don't know how viable that would be for you.
Or you could use Silverlight :-}