--- loncom/interface/lonhelper.pm	2005/10/17 19:46:12	1.124
+++ loncom/interface/lonhelper.pm	2005/10/17 20:21:31	1.125
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # .helper XML handler to implement the LON-CAPA helper
 #
-# $Id: lonhelper.pm,v 1.124 2005/10/17 19:46:12 albertel Exp $
+# $Id: lonhelper.pm,v 1.125 2005/10/17 20:21:31 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -2017,18 +2017,19 @@ BUTTONS
 	$mapUrl = $self->{MAP_URL};
     }
 
-    my @defaultSymbs;
+    my %defaultSymbs;
     if (defined($self->{DEFAULT_VALUE})) {
         my $valueFunc = eval($self->{DEFAULT_VALUE});
         die 'Error in default value code for variable ' . 
             $self->{'variable'} . ', Perl said: ' . $@ if $@;
-        @defaultSymbs = &$valueFunc($helper, $self);
-	if (!$multichoice) { # only allowed 1
+        my @defaultSymbs = &$valueFunc($helper, $self);
+	if (!$multichoice && @defaultSymbs) { # only allowed 1
 	    @defaultSymbs = ($defaultSymbs[0]);
 	}
+	%defaultSymbs = map { if ($_) {($_,1) } } @defaultSymbs;
+	delete($defaultSymbs{''});
     }
 
-
     # Create the composite function that renders the column on the nav map
     # have to admit any language that lets me do this can't be all bad
     #  - Jeremy (Pythonista) ;-)
@@ -2076,9 +2077,9 @@ BUTTONS
 	    }
 
             $col .= "<td align='center'><input type='$inputType' name='${var}.forminput' ";
-	    if (@defaultSymbs) {
+	    if (%defaultSymbs) {
 		my $symb=$resource->symb();
-		if (grep(/\Q$symb\E/,@defaultSymbs)) {
+		if (exists($defaultSymbs{$symb})) {
 		    $col .= "checked='checked' ";
 		    $checked = 1;
 		}