<form onsubmit="enable()">
<select name=c onchange="selectable()">
<optiong value=1>是</option>
<optiong value=0>否</option>
</select>
<select name=a>
</select>
<select name=b>
</select>
<input type=submit value=submit>
</form>
<script>
function check(){
with(document.all){
if(c.options[0].selected){
a.disabled=true;
b.disabled=false;
}
else if(c.options[1].selected){
a.disabled=false;
b.disabled=true;
}
}
}
function enable(){
document.all.a.disabled=true;
document.all.b.disabled=false;
}
</script>
<select name=c onchange="selectable()">
<optiong value=1>是</option>
<optiong value=0>否</option>
</select>
<select name=a>
</select>
<select name=b>
</select>
<input type=submit value=submit>
</form>
<script>
function check(){
with(document.all){
if(c.options[0].selected){
a.disabled=true;
b.disabled=false;
}
else if(c.options[1].selected){
a.disabled=false;
b.disabled=true;
}
}
}
function enable(){
document.all.a.disabled=true;
document.all.b.disabled=false;
}
</script>
{
case 1:
a.style.display="none";
b.style.display="";
break;
case 0:
a.style.display="";
b.style.display="none";
break;
}
<body>
<form onsubmit="enable()">
<select name=c onchange="selectable()">
<option></option>
<option value=1>是</option>
<option value=0>否</option>
</select>
<select name=a>
</select>
<select name=b>
</select>
<input type=submit value=submit>
</form>
</body>
<script>
function selectable(){
with(document.all){
if(c.options[0].selected){
a.disabled=true;
b.disabled=false;
}
else if(c.options[1].selected){
a.disabled=false;
b.disabled=true;
}
}
}
function enable(){
document.all.a.disabled=true;
document.all.b.disabled=false;
}
</script>
document.all.a.disabled=false;
document.all.b.disabled=false;
}
才對
抱歉
successful. When no options are selected, the control is not successful and
neither the name nor any values are submitted to the server when the form is
submitted.
如果没有一个option被选中,select不是successful.不会被提交
<body>
<form name=all method=post action=''>
<select name=c onchange="selectable()">
<option></option>
<option value=1>是</option>
<option value=0>否</option>
</select>
<select name=a>
<option value=1>AA</option>
<option value=0>AAAA</option>
</select>
<select name=b>
<option value=1>BB</option>
<option value=0>BBBB</option>
</select>
</form>
</body>
<script>
function selectable(){
with(document.all){
if(c.options[1].selected){
a.disabled=true;
b.disabled=false;
}
else if(c.options[2].selected){
a.disabled=false;
b.disabled=true;
}
}
}
</script>