window.onload = checkForm;

function checkForm() {

  var form = document.forms[0];

  if (form) {
    var regex = new RegExp("[\\?&]f=([^&#]*)");
    var qs = regex.exec(window.location.href);

    // parse qs
    if (qs != null) {
      var fn = qs[1].split(",");
      var i;

      for (i = 0; i < fn.length; i++) {
        var f = document.getElementsByName(fn[i]);
        if (f.length > 0) {
          f[0].style.background = "#fcc";
          f[0].style.border = "solid 1px #c77";
        }
      }

    }
  }

}

function adjustDays(oDayId, oMonthId, oYearId) {
  var oDay = document.getElementById(oDayId);
  var oMonth = document.getElementById(oMonthId);
  var oYear = document.getElementById(oYearId);

  if (oDay && oMonth && oYear) {
    var monthNo = oMonth.value;
    var year = oYear.value;
    var curDays = oDay.options.length;
    var newDays = getnDaysInMonth(monthNo - 1, year);
    var delta = newDays - curDays;
    if (delta < 0) {
      for (i = 0; i < -delta; i++) {
        //remove
        oDay.options.length--;
      }
    }
    if (delta > 0) {
      for (i = 0; i < delta; i++) {
        var opt = document.createElement("option");
        oDay.options.add(opt);
        opt.innerHTML = curDays + i + 1;
        opt.value = curDays + i + 1;
      }
    }
  }
}

var nDaysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
var nDaysInLeapMonth = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
function getnDaysInMonth(monthNo, year) {
  if ((year % 4) == 0) {
    if ((year % 100) == 0 && (year % 400) != 0)
      return nDaysInMonth[monthNo];

    return nDaysInLeapMonth[monthNo];
  } else
    return nDaysInMonth[monthNo];
}