function clickButton(e, buttonid){
      var evt = e ? e : window.event;
      var bt = document.getElementById(buttonid);
      if (bt){
          if (evt.keyCode == 13){
                bt.click();
                return false;
          }
      }
}

    
 function daysInMonth(month,year) 
    {
    var dd = new Date(year, month, 0);
    return dd.getDate();
    }
    
    function setDayDrop(dyear, dmonth, dday)
     {
        var year = dyear.options[dyear.selectedIndex].value;
        var month = dmonth.options[dmonth.selectedIndex].value;
        var day = dday.options[dday.selectedIndex].value;
        if (day != '')
         {
            var days = (year == '' || month == '') ? 31 : daysInMonth(month,year);
            dday.options.length = 0;
            dday.options[dday.options.length] = new Option('Day',0);
            for (var i = 1; i <= days; i++)
                dday.options[dday.options.length] = new Option(i,i);
         }
    }