日期:2014-05-16 浏览次数:20467 次
<html>
<title>考试申请</title>
<head>
</head>
<body>
<select id="selterm" onChange="changeterm()" style="width:100px">
<option>选择学期</option>
</select>
<select id="selclass" style="width:100px">
<option>选择课程</option>
</select>
<script type="text/javascript">
var termlist = [];
termlist['第一学期'] = ["c#","计算机基础","电子商务概论"];
termlist['第二学期'] = ["dreameaver","市场营销","网络","asp"];
var tmp = [];
var obj1 = document.getElementById('selterm');
var obj2 = document.getElementById('selclass');
for(var x in termlist){
obj1.add(new Option(x, null));
tmp.push(x);
}
function changeterm(){
var l = termlist[tmp[obj1.selectedIndex - 1]];
obj2.length = 1;
for(var i = 0, len = l.length; i< len; i++){
obj2.add(new Option(l[i], null));
}
}
</script>
</body>
</html>
------解决方案--------------------
<html>
<title>考试申请</title>
<head>
<script type="text/javascript">
var termlist = new Array();
termlist['第一学期'] = ["c#","计算机基础","电子商务概论"];
termlist['第二学期'] = ["dreameaver","市场营销","网络","asp"];
function changeterm() {
var term = document.getElementById('selterm').value;
var cls = document.getElementById('selclass'); //class是Javascript语言保留字,不能用作变量名
cls.options.length = 0;
for (var i in termlist) {
if (i == term) {
for(var j in termlist[i]) cls.options.add(new Option(termlist[i][j], termlist[i][j]));
}
}
}
window.onload = function() {
var obj = document.getElementById('selterm');
for(var i in termlist) obj.options.add(new Option(i, i));
}
</script>
</head>
<body>
<select id="selterm" onChange="changeterm()" style="width:100px">
<option>选择学期</option>
</select>
<select id="selclass" style="width:100px">
<option>选择课程</option>
</select>
</body>
</html>