Question

JS，<option>a</option>,a的值怎么取。

<select id="xl1" onchange="change()" >
<option >第一</option>
<option>第二</option>
</select>
<select id="xl2" onchange="change()" >
<option >第一</option>
<option>第二</option>
</select>
如果只有选择id=xl1中的“第二”才能显示出来id=xl2中的<select>我改怎么做？
我没分，我不过真是再这里卡住了，谢谢各位

Answer 1

<script type="text/javascript">
(function() {
var xl1,xl2
window.onload = function() {
xl1 = document.getElementById("xl1");
xl2 = document.getElementById("xl2");

xl1.onchange = xl2.onchange = change;
showItem(xl2, xl1.selectedIndex === 1);
};

function change(e) {
var e = e || window.event;
if( this === xl1 ) {
var b = this.selectedIndex === 1;
showItem(xl2, b)
}
}
function showItem(el, b) {
el.style.visibility = b?"visible":"hidden";
}
})();
</script>

Answer 2

window.onload = function(){
var oForm = document.forms[0], // 你可以用id
select1 = oForm.xl1, // xl1 ，xl2, 是select 的name
select2 = oForm.xl2 ;

select1.onchange = function(){
if(this.value == "1" ){
select2.style.display = "block";
}
}
}