<script>
function showmonth(){
//if(elYear.value!=""){
if(document.getElementById("year").value!=""){
for(var i=0;i<12;i++){
document.getElementById("month").options.add(new Option(i+1, i+1));
}
}
}
function showday(){
//var elDay=document.getElementById("day");
if(document.getElementById("month").value!="" && document.getElementById("year").value!=""){
document.getElementById("day").length=0;
for(var i=0;i<28;i++){
document.getElementById("day").options.add(new Option(i+1, i+1));
}
if(document.getElementById("month").value!="2"){
document.getElementById("day").options.add(new Option(29, 29));
document.getElementById("day").options.add(new Option(30, 30));
}
switch(document.getElementById("month").value){
case "1":
case "3":
case "5":
case "7":
case "8":
case "10":
case "12":{
document.getElementById("day").options.add(new Option(31, 31));
}
case "2":{
var nYear=document.getElementById("year").value;
if(nYear%400==0 || nYear%4==0 && nYear%100!=0)document.getElementById("day").options.add(new
Option(29, 29));
}
}
}
}
</script>
<tr>
<td></td><td bgcolor="#D5E8FD"><div align="left">出生日期:</div></td>
<!-- <td><input id="textcsrq" type="text" style="width:45%;"/></td> -->
<td><form name="f1">
<select id="year" name="year" style="width:80px" size="1" onChange="showmonth();showday()">
<script>
var yearbegin=1950,yearend=2020;
document.write("<option value='' selected>请选择年份...</option>")
for(var i=yearbegin;i<=yearend;i++){
document.write ("<option value="+i+">"+i+"</option>")
}
</script>
</select>
年
<select id="month" name="month" size="1" style="width:50px" onchange="showday();">
<option value="">请选择月份...</option>
</select>
月
<select id="day" name="day" size="1">
<option value="">请选择日期...</option>
</select>
日
</form></td>
</tr>