<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"
>
<html xmlns=
"http://www.w3.org/1999/xhtml"
>
<head>
<script type=
"text/javascript"
>
var
dom = window.document;
function
myYear() {
var
year = dom.getElementById(
"year"
);
var
minYear = 1900;
var
maxYear =
new
Date
().getFullYear();
for
(
var
i = minYear; i <= maxYear; i++) {
var
opt = dom.createElement(
"option"
);
opt.innerHTML = i;
opt.value = i;
year.appendChild(opt);
}
}
function
myMonth() {
var
month = dom.getElementById(
"month"
);
for
(
var
i = 1; i <= 12; i++) {
var
opt = dom.createElement(
"option"
);
if
(i < 10) {
opt.innerHTML =
"0"
+ i;
opt.value = i;
}
else
{
opt.innerHTML = i;
opt.value = i;
}
month.appendChild(opt);
}
month.onchange = myDay;
}
function
myDay() {
clear();
var
year = dom.getElementById(
"year"
).value;
var
month = dom.getElementById(
"month"
).value;
if
(year ==
""
) {
alert(
"请选择年"
);
return
;
}
if
(month ==
""
) {
alert(
"请选择月"
);
return
;
}
var
day = dom.getElementById(
"day"
);
for
(
var
i = 1; i <= 28; i++) {
var
opt = dom.createElement(
"option"
);
if
(i < 10) {
opt.innerHTML =
"0"
+ i;
opt.value =
"0"
+ i;
}
else
{
opt.innerHTML = i;
opt.value = i;
}
day.appendChild(opt);
}
var
isBigMonth = month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12;
var
isSmallMonth = month == 4 || month == 6 || month == 9 || month == 11;
var
isLeapYear = (year % 4 == 0 && year % 100 != 0) || year % 400 == 0;
if
(isBigMonth) {
for
(
var
i = 29; i <= 31; i++) {
var
opt = dom.createElement(
"option"
);
opt.innerHTML = i;
opt.value = i;
day.appendChild(opt);
}
}
else
if
(isSmallMonth) {
for
(
var
i = 29; i <= 30; i++) {
var
opt = dom.createElement(
"option"
);
opt.innerHTML = i;
opt.value = i;
day.appendChild(opt);
}
}
else
if
(isLeapYear) {
var
opt = dom.createElement(
"option"
);
opt.innerHTML = 29;
opt.value = 29;
day.appendChild(opt);
}
}
function
clear() {
var
day = dom.getElementById(
"day"
);
var
optArr = day.childNodes;
for
(
var
i = optArr.length - 1; i >= 0; i--) {
day.removeChild(optArr[i]);
}
}
function
getBirthday() {
var
dom = window.document;
myYear();
myMonth();
}
getBirthday();
</script>
<meta http-equiv=
"Content-Type"
content=
"text/html; charset=utf-8"
/>
<title>javascript</title>
</head>
<body>
生日:
<select id=
"year"
>
<option>年</option>
</select>
<select id=
"month"
>
<option>月</option>
</select>
<select id=
"day"
>
<option>日</option>
</select>
</body>
</html>