Since CGI.pm is a module, not built in, Perl has no way of knowing that those params are variables! Perl will only interpolate a scalar variable when it starts with $. Try one of these:

way one:

$Last = param('Last_Name');
print "Your last name is: $last\n";

way two, using the . (concentation operator):

print "Your last name is: ".param('Last_Name')."\n";
[download]

When's the last time you used duct tape on a duct? --Larry Wall