share/skin/default/layout/field/boolean.tt

   1 =extends field
   2
   3 =for layout field_body
   4
   5 value="1" [% is_checked %]
   6
   7 =for layout is_checked_yes
   8
   9 checked="checked"
  10
  11 =for layout is_checked_no
  12
  13 =cut