android emulator does not work

I installed jdk 1.7.0, eclipse and the android plugin. I create a new android project but when I try to launch I get this message:

[2011-08-09 18:24:15 - myTEst] ------------------------------
[2011-08-09 18:24:15 - myTEst] Android Launch!
[2011-08-09 18:24:15 - myTEst] adb is running normally.
[2011-08-09 18:24:15 - myTEst] Performing crr.myTest.MyTEstActivity activity launch
[2011-08-09 18:24:15 - myTEst] Automatic Target Mode: launching new emulator with compatible AVD 'myDev22'
[2011-08-09 18:24:15 - myTEst] Launching a new emulator with Virtua开发者_StackOverflowl Device 'myDev22'
[2011-08-09 18:24:15 - Emulator] invalid command-line parameter: Files.
[2011-08-09 18:24:15 - Emulator] Hint: use '@foo' to launch a virtual device named 'foo'.
[2011-08-09 18:24:15 - Emulator] please use -help for more information

I get the same message if I try to launch the emulator from the sdk manager. What does that mean? Thanks, Andrea.