--- loncom/homework/structuretags.pm	2006/04/20 03:35:06	1.351
+++ loncom/homework/structuretags.pm	2006/04/28 18:33:10	1.353
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # definition of tags that give a structure to a document
 #
-# $Id: structuretags.pm,v 1.351 2006/04/20 03:35:06 albertel Exp $
+# $Id: structuretags.pm,v 1.353 2006/04/28 18:33:10 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -331,9 +331,16 @@ Feedback Mode:
 }
 
 sub initialize_storage {
-    %Apache::lonhomework::results=();
-    %Apache::lonhomework::history=();
+    undef(%Apache::lonhomework::results);
+    undef(%Apache::lonhomework::history);
     my ($symb,$courseid,$domain,$name) = &Apache::lonxml::whichuser();
+    
+    # anonymous users (CODEd exams) have no data
+    if ($name eq 'anonymous' 
+	&& !defined($domain)) {
+	return;
+    }
+
     if ($env{'request.state'} eq 'construct' 
 	|| $symb eq ''
 	|| $Apache::lonhomework::type eq 'practice') {
@@ -353,6 +360,7 @@ sub initialize_storage {
 	%Apache::lonhomework::history=
 	    &Apache::lonnet::restore($symb,$courseid,$domain,$name);
     }
+
     #ignore error conditions
     my ($temp)=keys %Apache::lonhomework::history ;
     if ($temp =~ m/^error:.*/) { %Apache::lonhomework::history=(); }
@@ -440,13 +448,14 @@ sub checkout_msg {
                 'warning'=>'Checking out resources is subject to course policies, and may exclude future credit even if done erroneously.',
                 'checkout'=>'Check out Exam for Viewing',
 		'checkout?'=>'Check out Exam?');
+    my $uri = &Apache::lonenc::check_encrypt($env{'request.uri'});
     return (<<ENDCHECKOUT);
 <h2>$lt{'resource'}</h2>
     <p>$lt{'id_expln'}</p>
 <font color="red">
 <p>$lt{'warning'}</p>
 </font>
-<form name="checkout" method="POST" action="$env{'request.uri'}">
+<form name="checkout" method="POST" action="$uri">
 <input type="hidden" name="doescheckout" value="yes" />
 <input type="button" name="checkoutbutton" value="$lt{'checkout'}" onClick="javascript:if (confirm('$lt{'checkout?'}')) { document.checkout.submit(); }" />
 </form>
@@ -458,9 +467,10 @@ sub firstaccess_msg {
     my ($map)=&Apache::lonnet::decode_symb($symb);
     my $foldertitle=&Apache::lonnet::gettitle($map);
     &Apache::lonxml::debug("map is $map title is $foldertitle");
+    my $uri = &Apache::lonenc::check_encrypt($env{'request.uri'});
     return (<<ENDCHECKOUT);
 <h2>The resources in "$foldertitle" are open for a limited time. Once you click the 'Show Resource' button below you have $time to complete all resources "$foldertitle".</h2>
-<form name="markaccess" method="POST" action="$env{'request.uri'}">
+<form name="markaccess" method="POST" action="$uri">
 <input type="hidden" name="markaccess" value="yes" />
 <input type="button" name="accessbutton" value="Show Resource" onClick="javascript:if (confirm('Start Timer?')) { document.markaccess.submit(); }" />
 </form>