use NOT IN and a compound select statement:
SELECT table1.userid FROM table1
WHERE table1.userid NOT IN (SELECT table2.userid FROM table2)
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.