--- loncom/interface/lonnavmaps.pm	2009/11/23 14:56:07	1.439
+++ loncom/interface/lonnavmaps.pm	2009/12/27 01:31:05	1.441
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Navigate Maps Handler
 #
-# $Id: lonnavmaps.pm,v 1.439 2009/11/23 14:56:07 wenzelju Exp $
+# $Id: lonnavmaps.pm,v 1.441 2009/12/27 01:31:05 raeburn Exp $
 
 #
 # Copyright Michigan State University Board of Trustees
@@ -1528,7 +1528,6 @@ END
         ( $res->NETWORK_FAILURE    => 1,
           $res->NOTHING_SET        => 1,
           $res->CORRECT            => 1 );
-    my @backgroundColors = ("LC_trEven", "LC_trOdd");
 
     # Shared variables
     $args->{'counter'} = 0; # counts the rows
@@ -1763,7 +1762,6 @@ END
         # show them.
         foreach my $part (@parts) {
             $rownum ++;
-            my $backgroundColor = $backgroundColors[$rownum % scalar(@backgroundColors)];
             
             $result .= &Apache::loncommon::start_data_table_row();
 
@@ -3534,7 +3532,11 @@ sub navHash {
     my $self = shift;
     my $param = shift;
     my $id = shift;
-    return $self->{NAV_MAP}->navhash($param . ($id?$self->{ID}:""));
+    my $arg = $param . ($id?$self->{ID}:"");
+    if (defined($arg)) {
+        return $self->{NAV_MAP}->navhash($arg);
+    }
+    return;
 }
 
 =pod