function fix_date(id) {
  var date = document.getElementById(id);

  var month = document.getElementById(id + "_month");
  var day = document.getElementById(id + "_day");
  var year = document.getElementById(id + "_year");

  if (date) {
    date.value = 
      year.options[year.selectedIndex].value + "-" + 
      month.options[month.selectedIndex].value + "-" + 
      day.options[day.selectedIndex].value;
  }
}

function fix_datetime(id) {
  var date = document.getElementById(id);

  var month = document.getElementById(id + "_month");
  var day = document.getElementById(id + "_day");
  var year = document.getElementById(id + "_year");
  var hour = document.getElementById(id + "_hour");
  var minute = document.getElementById(id + "_minute");

  if (date) {
    date.value = 
      year.options[year.selectedIndex].value + "-" + 
      month.options[month.selectedIndex].value + "-" + 
      day.options[day.selectedIndex].value + " " + 
      hour.options[hour.selectedIndex].value + ":" + 
      minute.options[minute.selectedIndex].value + ":00";
  }
}

function hide(id) {
  var element = document.getElementById(id);

  if (element) {
    element.style.display='none';
  }
}

function show(id) {
  var element = document.getElementById(id);

  if (element) {
    element.style.display='';
  }
}