sub clean_list {

	my @array_with_duplicates=(@_);
	my @array_no_duplicates;

	my $previous = '';
	while (scalar @array_with_duplicates > 0) 
	{
   		my $next = shift(@array_with_duplicates);
   		if ($previous ne $next) 
   		{
     		push(@array_no_duplicates, $next);
     		$previous = $next;
   		}
	}