SQL statement for 2 tables?

I have two tables: GroupName and SelectGroup

GroupName:


SelectGroup:


on my website, I have dropdown menu box that display the data from table: GroupName.

What I like to do is on the dropdown menu only display the items that has not been selected by that UserID. The UserID is just a URL querystring.

Can someone please help me how to do about this?

Thanks

Found my solution here

SELECT a.i
FROM #a AS a
WHERE a.i NOT IN (SELECT b.j FROM #b AS b)
OR a.i IS NULL

remove OR a.i IS NULL