下拉列表实现多级联动
<select name="courseName" onChange="set_class(this, this.form.clazz);">
<option value="0">选择课程名称</option>
<option value="语文">语文</option>
<option value="数学">数学</option>
<option value="英语">英语</option>
<option value="计算机">计算机</option>
<option value="美术">美术</option>
<option value="音乐">音乐</option>
</select>
<select name="clazz" >
<option value="0">选择班级</option>
</select>
<script type="text/javascript">
classes = new Object();
classes['语文']=new Array('语文1班', '语文2班');
classes['数学']=new Array('数学1班', '数学2班');
classes['英语']=new Array('英语1班', '英语2班');
classes['计算机']=new Array('计算机1班', '计算机2班');
classes['美术']=new Array('美术1班', '美术2班');
classes['音乐']=new Array('音乐1班', '音乐2班');
function set_class(courseName, clazz)
{
var courseValue, classValue;
var i;
courseValue=courseName.value;
for(i=0; i<classes[courseValue].length; i++)
{
clazz.options[i] = new Option();
clazz.options[i].text = classes[courseValue][i];
clazz.options[i].value = classes[courseValue][i];
}
}
</script>