how to purge all from javascript?

Hi,

I tested this line alone in a single script with nothing else. When I go to check it out, to Edit/Purge/All Memory & Disk Cache I can still see it full of cached files.

Is this the correct syntax? Anything else that I should do to effectively clear all?

Please, let me know.

app.purge(PurgeTarget.ALL_CACHES);

I should add that I tried this way too, still with no luck:

app.findMenuCommandId("All Memory & Disk Cache...")

Thank you,

A.