--- loncom/interface/loncommon.pm	2003/10/30 13:57:06	1.140
+++ loncom/interface/loncommon.pm	2003/11/03 21:29:23	1.141
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.140 2003/10/30 13:57:06 matthew Exp $
+# $Id: loncommon.pm,v 1.141 2003/11/03 21:29:23 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -2672,11 +2672,14 @@ sub check_if_partid_hidden {
     my ($id,$symb,$udom,$uname) = @_;
     my $hiddenparts=&Apache::lonnet::EXT('resource.0.hiddenparts',
 					 $symb,$udom,$uname);
+    my $truth=1;
+    #if the string starts with !, then the list is the list to show not hide
+    if ($hiddenparts=~s/^\s*!//) { $truth=undef; }
     my @hiddenlist=split(/,/,$hiddenparts);
     foreach my $checkid (@hiddenlist) {
-	if ($checkid =~ /^\s*\Q$id\E\s*$/) { return 1; }
+	if ($checkid =~ /^\s*\Q$id\E\s*$/) { return $truth; }
     }
-    return undef;
+    return !$truth;
 }