sub lc_filenames{
   my($dir)=@_;
   $dir||="./"; #sets to current directory if it wasn't passed a parameter
   opendir DIR, $dir;
   while(defined($file=readdir DIR)){
      if(-f ($dir.$file)){
         if($file=~/[A-Z]/){
            $newname=lc($file);
            if(-e ($dir.$filename)){
                print "File exists. Replace it? Y/N\n";
                if(<> and /^y/i){
                   rename($dir.$file,$dir.$newname);
                }
            } else{
               rename($dir.$file,$dir.$newname);
            }
         }
      }
   }
}