function setDays(form)
{
  birthYear = parseInt(form.birthYear.options[form.birthYear.selectedIndex].value);
  birthMonth = form.birthMonth.selectedIndex - 1;
  birthDay = form.birthDay.selectedIndex;
  form.birthDay.options.length = 0;
  var days = new Array(31, ((birthYear % 4 == 0 && birthYear % 100 != 0) || birthYear % 400 == 0 ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
  for(i = 0; i < days[birthMonth]; i++)
  { 
    form.birthDay.options.length = form.birthDay.options.length + 1;
    form.birthDay.options[i].value = i + 1;
    form.birthDay.options[i].text = i + 1;
  }
  form.birthDay.selectedIndex = (birthDay < form.birthDay.options.length) ? birthDay : form.birthDay.options.length - 1;
}

function setYear(thisYear)
{
 	   var yearMax = thisYear - 16;
  	   var yearMin = thisYear - 85;

   var form = document.getElementById("form1");
   var options = "";
   
   options = '<option value=""> - year - </option>';
   for (i = yearMax; i > yearMin; i--)
   {   
    options += '<option value="' + (i) + '">' + (i) + '</option>';
   }
 
   form.birthYear.innerHTML = options;
}

function setUpper_age_pref(form)
{
   var selObj = document.getElementById('lower_age_pref');
	var selIndex = selObj.selectedIndex;

 	   var minAge = selObj.options[selIndex].value;
  	   var maxAge = 80;

   var form = document.getElementById("form1");
   var options = "";

   for (i = minAge; i < maxAge;)
   {
    i++;
    options += '<option value="' + (i) + '">' + (i) + '</option>';
   }

   form.upper_age_pref.innerHTML = options;
}