EasyUI datagrid隐藏表头

<div id="IMSIS" class="easyui-tabs" style="padding:2px;">
					<div title="设备" style="padding:0px">
						<table class="easyui-datagrid" style="width:auto;height:auto;">
							<thead>
								<tr>
									<th data-options="field:'itemid',width:203"><b style="color:#505050">SIM卡号</b></th>
									<th data-options="field:'productid',width:203"><b style="color:#505050">IMSI</b></th>
								</tr>
							</thead>
							<tbody>
							
								<tr style="display: none;"><td><b style="color:#505050">SIM卡号</b></td><td><b style="color:#505050">IMSI</b></td></tr>

							</tbody>
						</table>
					</div>

<style type="text/css">
    	/* 隐藏表格表头 */
		#IMSIS .datagrid-header {
			position: absolute; visibility: hidden;
		}
				
	</style>