12EasyUI 菜单与按钮- 创建分割按钮（Split Button）

<div style="border:1px solid #ccc;background:#fafafa;padding:5px;width:120px;">
        <a href="#" class="easyui-splitbutton" menu="#mm" iconCls="icon-edit">Edit</a>
        <a href="#" class="easyui-linkbutton" plain="true" iconCls="icon-help"></a>
    </div>
    <div id="mm" style="width:150px;">
        <div iconCls="icon-undo">Undo</div>
        <div iconCls="icon-redo">Redo</div>
        <div class="menu-sep"></div>
        <div>Cut</div>
        <div>Copy</div>
        <div>Paste</div>
        <div class="menu-sep"></div>
        <div>
            <span>Open</span>
            <div style="width:150px;">
                <div>Firefox</div>
                <div>Internet Explorer</div>
                <div class="menu-sep"></div>
                <div>Select Program...</div>
            </div>
        </div>
        <div iconCls="icon-remove">Delete</div>
        <div>Select All</div>
    </div>