[OpenLayers-Users] Status of tiles

[francescoboccacci at libero.it]

Hi all,
i have a question (i don't know if is possible). I would like to know if the 
tiles that are showed come from my cache or directly from the server.
In my code i use OpenLayers.Layer.OSM layer and i would like to capture the 
header (status 200 OK or 304 ) of the response.
It is possible?

Thanks

Francesco