<body>
<select id=s1 multiple="multiple" size="7">
<option>123</option>
<option>234</option>
<option>456</option>
<option>678</option>
<option>890</option>
</select>
<input type="button" id="r" value="向右" />
<input type="button" id="l" value="向左" />
<select id=s2 multiple="multiple" size="7">
<option>asd</option>
<option>qwe</option>
<option>fed</option>
<option>sfg</option>
<option>ghj</option>
</select><br />
<input type="text" id="txt" />
<input type="button" id="b" value="添加" />
</body>
</html>
<script>
var s1=document.getElementById("s1");
var r=document.getElementById("r");
var l=document.getElementById("l");
var s2=document.getElementById("s2");
var txt=document.getElementById("txt");
var b=document.getElementById("b");
//在输入框中添加内容
b.onclick=function(){
if (txt.value.trim()!="") {
var op=document.createElement("option");
op.innerText=txt.value;
s1.appendChild(op);
txt.value="";
}
}
//向右移动内容
r.onclick=function(){
s2.appendChild(s1.selectedOptions[0]);
}
//向左移动内容
l.onclick=function(){
s1.appendChild(s2.selectedOptions[0]);
}