简单实现jQuery级联菜单

.button {
 border: 1px ridge #ffffff;
 line-height:18px;
 height: 20px;
 width: 45px;
 padding-top: 0px;
 background:#CBDAF7;
 color:#000000;
 font-size: 9pt;
} 

<div style="border:1px dashed #E6E6E6;margin:150px 0px 0px 450px; width:280px; height:200px; background-color:#E6E6E6;">
<table width="285" height="169" border="0" align="left" cellpadding="0" cellspacing="0" style="margin:15px 0px 0px 15px;">
<tr>
<td width="126">
<select name="first" size="10" multiple="multiple" class="td3" id="first">
<option value="选项1">选项1</option>
<option value="选项2">选项2</option>
<option value="选项3">选项3</option>
<option value="选项4">选项4</option>
<option value="选项5">选项5</option>
</select> 
</td>
<td width="69" valign="middle">
<input name="add" id="add" type="button" class="button" value="-->" /> 
<input name="add_all" id="add_all" type="button" class="button" value="==>" />
<input name="remove" id="remove" type="button" class="button" value="<--" />
<input name="remove_all" id="remove_all" type="button" class="button" value="<==" />
</td>
<td width="127" align="left">
<select name="second" size="10" multiple="multiple" id="second">
<option value="选项6">选项6</option>
</select>
</td>
</tr>
</table>

$(document).ready(function(){

$("#add").click(function(){
 $("#first option:selected").appendTo($("#second"));
});

$("#add_all").click(function(){
 $("#first option").appendTo($("#second"));
});

$("#remove").click(function(){
 $("#second option:selected").appendTo($("#first"));
});

$("#remove_all").click(function(){
 $("#second option").appendTo($("#first"));
});
});