my $parser = XML::LibXML->new();
	my $doc = $parser->parse_file($file);
	$root = $doc->documentElement();
	$cdoc = $doc->getElementsById($docname);
	open(FH, ">", $file) or die "Open file '$tracefile' failed: $!\n";
	flock(FH, LOCK_SH);
	seek(FH, 0, SEEK_SET);
	
	for my $para ($document->getElementsByTagName ("p")){
		my $status = processing($para);
		
		my @paras = $root->getElementsByTagName('sentence');
		my $exist_para = $root->getElementsById($para->getAttribute("id"));
		my $para_elem;
		if(!defined($exist_para)){
			$para_elem = $root->createElement('sentence');
			$para_elem->setAttribute('xml:id', $para->getAttribute("id"));
			$para_elem->setAttribute('index', scalar(@paras));
		}else{
			$para_elem = $exist_para;
		}
		if($status == 1){
			$para_elem->setAttribute('class', 'problem');
		}elsif($status == 0){
			$para_elem->setAttribute('class', 'fine');
		}else{
			$para_elem->setAttribute('class', 'skip');			
		}
		$cdoc->appendChild($para_elem);
	}