--- trunk/lib/WebPAC/Normalize.pm	2006/07/07 21:48:09	589
+++ trunk/lib/WebPAC/Normalize.pm	2006/07/09 15:22:30	592
@@ -710,7 +710,7 @@
 =cut
 
 sub prefix {
-	my $p = shift or die "prefix needs string as first argument";
+	my $p = shift or return;
 	return map { $p . $_ } grep { defined($_) } @_;
 }