--- loncom/xml/lonplot.pm	2013/01/21 02:25:38	1.171
+++ loncom/xml/lonplot.pm	2013/01/31 17:10:38	1.172
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.171 2013/01/21 02:25:38 raeburn Exp $
+# $Id: lonplot.pm,v 1.172 2013/01/31 17:10:38 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1984,7 +1984,7 @@ sub write_gnuplot_file {
     #
     my $linestyle_index = 50;
     my $line_width   = '';
-    my $plots;
+    my $plots = '';
 
     # If arrows are needed there will be an arrow style for each as well:
     #
@@ -1993,8 +1993,11 @@ sub write_gnuplot_file {
 
     for (my $i = 0;$i<=$#curves;$i++) {
 	$curve = $curves[$i];
-	my $plot_command;
-	my $plot_type = ', ' if ($i > 0);
+	my $plot_command = '';
+	my $plot_type = '';
+	if ($i > 0) {
+	    $plot_type = ', ';
+	}
 	if ($target eq 'tex') {
 	    $curve->{'linewidth'} *= 2;
 	}