--- loncom/homework/lonhomework.pm	2005/08/29 19:28:43	1.218
+++ loncom/homework/lonhomework.pm	2005/11/08 17:53:20	1.219
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # The LON-CAPA Homework handler
 #
-# $Id: lonhomework.pm,v 1.218 2005/08/29 19:28:43 albertel Exp $
+# $Id: lonhomework.pm,v 1.219 2005/11/08 17:53:20 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -615,6 +615,7 @@ sub analyze {
     &Apache::lonxml::debug("Analyze");
     my $result;
     my %overall;
+    my %seedexample;
     my %allparts;
     my $rndseed=$env{'form.rndseed'};
     &analyze_header($request);
@@ -627,9 +628,10 @@ sub analyze {
 	&Apache::lonhtmlcommon::Increment_PrgWin($request,\%prog_state,
 						 &mt('last problem'));
 	if (&Apache::loncommon::connection_aborted($request)) { return; }
+        my $thisseed=$i+$rndseed;
 	my $subresult=&Apache::lonnet::ssi($request->uri,
 					   ('grade_target' => 'analyze'),
-					   ('rndseed' => $i+$rndseed));
+					   ('rndseed' => $thisseed));
 	(my $garbage,$subresult)=split(/_HASH_REF__/,$subresult,2);
 	my %analyze=&Apache::lonnet::str2hash($subresult);
 	my @parts;
@@ -641,8 +643,13 @@ sub analyze {
 	    if ($analyze{$part.'.type'} eq 'numericalresponse'	||
 		$analyze{$part.'.type'} eq 'stringresponse'	||
 		$analyze{$part.'.type'} eq 'formularesponse'   ) {
+		my $concatanswer=join("\0",@{ $analyze{$part.'.answer'} });
+		if (($concatanswer eq '') || ($concatanswer=~/^\@/)) {
+		    @{$analyze{$part.'.answer'}}=('<font color="red">'.&mt('Error').'</font>');
+		}
 		push( @{ $overall{$part.'.answer'} },
 		      [@{ $analyze{$part.'.answer'} }]);
+                $seedexample{join("\0",@{ $analyze{$part.'.answer'}})}=$thisseed;
 	    }
 	}
     }
@@ -652,17 +659,18 @@ sub analyze {
     foreach my $part (sort(keys(%allparts))) {
 	if (defined(@{ $overall{$part.'.answer'} })) {
 	    my $num_cols=scalar(@{ $overall{$part.'.answer'}->[0] });
-	    $request->print('<table><tr><th colspan="'.($num_cols+1).'">'.&mt('Part').' '.$part.'</th></tr>');
+	    $request->print('<table border="1"><tr><th colspan="'.($num_cols+1).'">'.&mt('Part').' '.$part.'</th></tr>');
 	    my %frequency;
 	    foreach my $answer (sort {$a->[0] <=> $b->[0]} (@{ $overall{$part.'.answer'} })) {
 		$frequency{join("\0",@{ $answer })}++;
 	    }
-	    $request->print('<tr><th colspan="'.($num_cols).'">'.&mt('Answer').'</th><th>'.&mt('Frequency').'</th></tr>');
+	    $request->print('<tr><th colspan="'.($num_cols).'">'.&mt('Answer').'</th><th>'.&mt('Frequency').'<br />('
+			    .&mt('click for example').')</th></tr>');
 	    foreach my $answer (sort {(split("\0",$a))[0] <=> (split("\0",$b))[0]} (keys(%frequency))) {
-		$request->print('<tr><td align="right">'.
-				join('</td><td align="right">',split("\0",$answer)).
-				'</td><td>('.$frequency{$answer}.
-				')</td></tr>');
+		$request->print('<tr><td>'.
+				join('</td><td>',split("\0",$answer)).
+				'</td><td><a href="'.$request->uri.'?rndseed='.$seedexample{$answer}.'">'.$frequency{$answer}.
+				'</a></td></tr>');
 	    }
 	    $request->print('</table>');
 	} else {