add style to header

booking.variety_admin.inc

@@ -547,6 +547,9 @@ function booking_varietysessions_csv_report($timeslot_id) {
   $nullToMysqlNull = true;
   $delimiter_esc = preg_quote($delimiter, '/');
   $enclosure_esc = preg_quote($enclosure, '/');
+  // List of style options at https://github.com/mk-j/PHP_XLSXWriter/issues/198
+  $header_style = array( 'border'=>'bottom','border-style'=>'medium', 'border-color'=>'#000000',
+   'valign'=>'top', 'color'=>'#FFFFFF', 'fill'=>'#4A8C42', 'font-style' => 'bold');
 
   //get the list of variety session memberships
   $session_members_query = db_query("SELECT r.*, p.* FROM {booking_variety_regn} r
@@ -637,7 +640,7 @@ function booking_varietysessions_csv_report($timeslot_id) {
   $writer = new XLSXWriter();
   $writer->setAuthor($event->booking_eventname); 
   //Add the header row
-  $writer->writeSheetHeader($sheetname, $column_headings);
+  $writer->writeSheetHeader($sheetname, $column_headings, $header_style);
 
   //Add the data
   foreach($rows as $row) {