use CGI;
my $query=CGI::new();
my %config;
my @params;
if($query->param('submit') eq "save"){
   #if we want to save new parameters open log file 
   #and read old settings into config hash
   if("test.cfg" -e){
       open FILE, "<test.cfg" || die "Can't open $!";
       while(<FILE>){
         if(/(.*)=(.*)/){
            $config{$1}=$2;
         }
      }
      close FILE;
   }
   @params=$query->param();

   #add/overwrite params just submitted in config hash
   foreach(@params){
      $config{$_}=$query->param($_) unless $_ eq "submit";
   }
   #write all the config key/value pairs out to the file
   open FILE, ">test.cfg" || die "Can't open! $!";
   foreach(keys %config){
      print FILE "$_=$config{$_}\n";
   }
   close FILE;
}