例:
<select name=s1>
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select><select name=s2>
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>第二个SELECT菜单中肯定有个(option之间的值是“a”,但option.value=多少,不知道)要求:当s1的值为‘学生’的被选上后,s2.option之间的text为‘a'的这个也应该被选上请教,怎么写
<select name=s1>
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select><select name=s2>
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>第二个SELECT菜单中肯定有个(option之间的值是“a”,但option.value=多少,不知道)要求:当s1的值为‘学生’的被选上后,s2.option之间的text为‘a'的这个也应该被选上请教,怎么写
var $ = function(id){return document.getElementById(id);};
window.onload=function()
{
$("s1").attachEvent("onchange",function(obj){
if(obj.srcElement.value=="学生")
{
var len = $("s2").options.length;
for(i=0;i<len;i++)
{
if($("s2").options[i].text=="a")
{
$("s2").options[i].selected=true;
break;
}
}
}else
{
$("s2").value="";
}
});
}
</script><select name=s1>
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select><select name=s2>
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript">
function sel(){
var s1=document.getElementById("s1");
var s2=document.getElementById("s2");
s1.onchange=function(){
if(this.options[this.selectedIndex].value=="学生"){
for(var i=0,len=s2.options.length;i<len;i++){
if(s2.options[i].text=="a"){
s2.options[i].selected=true;
break;
}
}
}
}
}
window.onload=sel;
</script>
</head><body>
<select name="s1" id="s1">
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select><select name="s2" id="s2">
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript">
function sel(){
var s1=document.getElementById("s1");
var s2=document.getElementById("s2");
s1.onchange=function(){
if(this.options[this.selectedIndex].value=="学生"){
for(var i=0,len=s2.options.length;i<len;i++){
if(s2.options[i].text=="a"){
s2.options[i].selected=true;
break;
}
}
}
else{
s2.value="";
}
}
}
window.onload=sel;
</script>
</head><body>
<select name="s1" id="s1">
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select><select name="s2" id="s2">
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
</head><body>
<div>
<select name="s1" onchange="change();">
<option value="老师">老师</option>
<option value="学生">学生</option>
<option value="职工">职工</option>
</select>
<select name="s2">
<option value="1">1</option>
<option value="2">2</option>
<option value="5">a</option>
<option value="4">4</option>
</select>
</div>
</body><script type="text/javascript" language="javascript">
function change(){
if(document.getElementsByName("s1")[0].selectedIndex == 1) {
document.getElementsByName("s2")[0].options[2].selected = true;
}
}
</script></html>
页面在打开时,S1选的就是‘学生’,能不能s2.options[i].selected=true;也在页面打开时就这样被选上
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<script type="text/javascript">
function sel(){
var s1=document.getElementById("s1");
var s2=document.getElementById("s2");
s1.onchange=aa;
function aa(){
if(s1.options[s1.selectedIndex].value=="学生"){
for(var i=0,len=s2.options.length;i<len;i++){
if(s2.options[i].text=="a"){
s2.options[i].selected=true;
break;
}
}
}
else{
s2.value="";
}
}
aa();
}
window.onload=sel;
</script>
</head><body>
<select name="s1" id="s1">
<option value="学生">学生</option>
<option value="老师">老师</option>
<option value="职工">职工</option>
</select><select name="s2" id="s2">
<option value="">...</option>
<option value="">...</option>
<option value="5">a</option>
<option value="">...</option>
</select>
</body>
</html>