Month:<select onchange="show()" id=month><option>select</option><script>for(i=1;i<13;i++)document.write("<option>"+i+"</option>");</script></select>
Days: <select id=days><option>show</option><script>for(i=28;i<32;i++)document.write("<option>"+i+"</option>");</script></select>
<script>
function show(){
if(isNaN(parseInt(month.innerText)))return false
switch(parseInt(month.options[month.selectedIndex].innerText)){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
days.options[4].selected=true;
break;
case 4:
case 6:
case 9:
case 11:
days.options[3].selected=true;
break;
case 2: //由年份决定;
break;
}
}
</script>
Days: <select id=days><option>show</option><script>for(i=28;i<32;i++)document.write("<option>"+i+"</option>");</script></select>
<script>
function show(){
if(isNaN(parseInt(month.innerText)))return false
switch(parseInt(month.options[month.selectedIndex].innerText)){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
days.options[4].selected=true;
break;
case 4:
case 6:
case 9:
case 11:
days.options[3].selected=true;
break;
case 2: //由年份决定;
break;
}
}
</script>
for(i=1;i<=12;i++)
document.write((new Date(2003,i,0)).getDate()+"<br>");