Use 'True' and 'False' for booleans

gluon/sqlhtml.py

@@ -1882,8 +1882,8 @@ class SQLFORM(FORM):
           var $value_item = jQuery('#%(value_id)s_'+b);
           if ($value_item.is(':checkbox')){
             if  ($value_item.is(':checked'))
-                    value = 'on';
+                    value = 'True';
-            else  value = 'off';
+            else  value = 'False';
           }
           else
           { value = $value_item.val().replace('"','\\\\"')}