匿名Fluid Layout
Percentage width of region panel in a layout.
示例：
代码：
<div class="easyui-layout" style="width:700px;height:350px;">
<div id="p" data-options="region:'west'" title="West" style="width:30%;padding:10px">
<p>width: 30%</p>
</div>
<div data-options="region:'center'" title="Center">
</div>
</div>