function isLeapYear(y){y=parseInt(y);return ((y%4==0&&y%100!=0)||y%400==0)}function fillList(mc,dd){var cs=dd.selectedIndex;dd.length=0;var c=0;for (c=1;c<=mc;c++){var x=c.toString();if (x.length==1)  x='0'+x;dd.options[c-1]=new Option(x,x);}if (cs<=dd.options.length) dd.selectedIndex=cs;else dd.selectedIndex=dd.options.length-1;}function lengthOfMonth(yy,mm){var mc=31;var sm=mm.selectedIndex;if (sm==3 || sm==5 || sm==9 || sm==10) mc=30;if (sm==1) mc=28;if (isLeapYear(yy.value) && sm==1) mc=29;return mc;}function chkMnth(e){var yy=document.getElementById(e.name.replace('ddlMonth','ddlYear'));var mm=e;var dd=document.getElementById(e.name.replace('ddlMonth','ddlDay'));fillList(lengthOfMonth(yy,mm),dd);}function chkYr(e){var yy=e;var dd=document.getElementById(e.name.replace('ddlYear','ddlDay'));if (isLeapYear(yy.value) && dd.options.length==28) fillList(29,dd);}