How to create a legend containing ONLY classes shown in current map?

[Daniele Margotti]

Hi,
I have another question about the legend...

How can I tell CGI Mapserver to create a legend containing ONLY classes
that are visible in the current map?

Now I get a legend that contains ALL classes of the selected layer, even
if I have zoomed to a very close scale (and I view only one class in the
map).

Can you help me?
Is it possible?

Thank you,
  Daniele