Queens Gambit Declined (Trap#2)

1. d4 d5
2. c4 e6
3. Nc3 Nf6
4. Bg5 Nd7
5. Nf3 Bb4
6. Bxf6 Nxf6? (when Black plays Nd7 they often do it to protect the Knight on f6 - but this doesn't work here ... )
7. Qa4+ (wins Bishop on b4 - White should win now)