jqGrid 点击查询按钮后弹出的覆盖层总是把表格挤下去了

在使用jqGrid 控件时出现只要点击弹出框，在弹出框弹出后有个层来覆盖整个页面，但是这个层没有覆盖网页，而是把jqGrid表格挤到下面去了整了半天了，都解决不了，哪为高手帮忙看看。 js代码:<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib tagdir="/WEB-INF/tags/simpletable" prefix="simpletable"%>
<%@ taglib uri="http://www.rapid-framework.org.cn/rapid" prefix="rapid" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<c:set var="ctx" value="${pageContext.request.contextPath}"/><head>
<link href="<c:url value="/css/redmond/jquery-ui-1.8.2.custom.css"/>" type="text/css" rel="stylesheet">
<link href="<c:url value="/css/ui.jqgrid.css"/>" type="text/css" rel="stylesheet">
<link href="<c:url value="/css/jquery.searchFilter.css"/>" type="text/css" rel="stylesheet">
<script src="<c:url value="/js/jquery-1.7.1.min.js"/>" type="text/javascript"></script>
<script src="<c:url value="/js/jquery-ui-1.8.2.custom.min.js"/>" type="text/javascript"></script>
<script src="<c:url value="/js/i18n/grid.locale-en.js"/>" type="text/javascript"></script>
<script src="<c:url value="/js/jquery.jqGrid.min.js"/>" type="text/javascript"></script><style>
html,body{
margin: 0;
padding: 0;
font-size: 75%
}
</style></head>
<body>
<div style="left:93px;top:60px;z-index:1">
<table id="rowed3"></table>
<div id="prowed3"></div>
</div>
<br />
<script  type="text/javascript">
jQuery("#rowed3").jqGrid({
    url:'${ctx}/competitioncode/test',
datatype: "json",
    colNames:['Inv No','Date', 'Client', 'Amount','Tax','Total','Notes'],
    colModel:[
    {name:'id',index:'id', width:100},
    {name:'invdate',index:'invdate', width:90, editable:true},
    {name:'name',index:'name', width:100,editable:true},
    {name:'amount',index:'amount', width:80, align:"right",editable:true},
    {name:'tax',index:'tax', width:120, align:"right",editable:true},
    {name:'total',index:'total', width:80,align:"right",editable:true},
    {name:'note',index:'note', width:150, sortable:false,editable:true,edittype:"select",editoptions:{value:"N:未使用;Y:使用"}}
    ],
    rowNum:10,
    rowList:[10,20,30],
    pager: '#prowed3',
    sortname: 'id',
    viewrecords: true,
    multiselect: true,
    sortorder: "desc",
editurl: "${ctx}/competitioncode/whowShose",
caption: "Using navigator"
});
jQuery("#rowed3").jqGrid('navGrid',"#prowed3",{edit:true,add:false,del:false});
jQuery("#rowed3").jqGrid('inlineNav',"#prowed3");</script></body>