--- loncom/homework/caparesponse/caparesponse.pm	2004/02/19 21:49:33	1.132
+++ loncom/homework/caparesponse/caparesponse.pm	2004/02/20 18:04:43	1.133
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # caparesponse definition
 #
-# $Id: caparesponse.pm,v 1.132 2004/02/19 21:49:33 sakharuk Exp $
+# $Id: caparesponse.pm,v 1.133 2004/02/20 18:04:43 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -514,6 +514,16 @@ sub get_sigrange {
 	}
 	if (!$sig_ubound) { $sig_ubound=$sig_lbound; }
     }
+    if (($sig_ubound<$sig_lbound) ||
+	($sig_lbound > 15) ||
+	($sig =~/(\+|-)/ ) ) {
+	my $errormsg=&mt("Invalid Significant figures detected")." ($sig)";
+	if ($ENV{'request.state'} eq 'construct') {
+	    $errormsg.=
+		&Apache::loncommon::help_open_topic('Significant_Figures');
+	}
+	&Apache::lonxml::error($errormsg);
+    }
     return ($sig_ubound,$sig_lbound);
 }