sub pq {
	my $num = shift (@_) || 0;
	my $stellen = shift (@_) || 0;
	my $vorzeichen = '';
	my $rounded = '0';
	if ($stellen >= 0 && $stellen <= 9 && !($num =~ /[^+-\.0-9]/)) {
		if (substr ($num,0,1) eq '-' || substr ($num,0,1) eq '+') {
			$vorzeichen = '-' if substr ($num,0,1) eq '-';
			$num = substr ($num,1);
		}
		$rounded = int( $num * (10 ** $stellen) + 0.5 ) / 10 ** $stellen;
	}
	return ($rounded ne '0' ? $vorzeichen : '') . $rounded;
}