When I run your code, I get a lot of

[Mon Mar 16 23:05:22 2009] pm: Use of uninitialized value $ENV in conc
+atenation (.) or string [...]
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errors. Perhaps you should have used

    print "$key = $ENV{ $key }<br>";
#                     ^------^ braces, not parentheses
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instead (which also includes moritz's suggestion).