sub print_log
{
   my $string = shift;
   my $logfile = "PATH\FILENAME";
   $! = 0;
   unless(open(LOG, ">>", $logfile))
   {
      print "Konnte Logfile nicht oeffnen: $!\n";
      exit 1; 
   }
   print $string;
   print LOG $string;
   close(LOG);
}