Dumping vars from CGI with Data::Dumper

I am trying to read the values of all the parameters received in a CGI.

But even using a Data::Dumper::Simple module, only the names of the  
params are displayed, not the name/value relation of each one.

use Data::Dumper::Simple;
use CGI;
print Dumper(\@param);

any idea what I am doing wrong? I tryied with Data::Dumper::Names and  
same result.