<!--
var chk_flag = "false";
function switch_checkbox(field) {
  if (chk_flag == "false") {
    for (i = 0; i < field.length; i++) {
      field[i].checked = true;
    }
    chk_flag = "true";
  }
  else {
    for (i = 0; i < field.length; i++) {
      field[i].checked = false;
    }
    chk_flag = "false";
  }
}
//-->