You need to print out a Content-Type header for your if condition, not just your else. You can/should use the header method in CGI.pm:

    print $query->header;
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That'll print out the HTTP header for you.

Also, when I just pasted in your code, it didn't compile, because you didn't declare $key, and you used strict. You can use

    foreach my $key
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to fix that.