JS隐藏显示查询面

jsp:

<table border="0" cellpadding="0" cellspacing="0"      class="simpleFormTable" width="100%">
      <tr>
       <td class="tableTitle3" style="cursor: pointer;"
        onclick="showHide('queryUserZone',this)">
        &nbsp;<font size="4" color="red">-</font><font color="red"
         style="font-weight: bold"> 隐藏查询条件</font>
       </td>
      </tr>
      <tr id="queryUserZone" style="display: block;">
       <td class="formTableC">
        <table align="center" border="0" cellpadding="0" cellspacing="1"
         id="tab" width="100%">
         <tr>
          <td class="td1">
           办件编号：
          </td>
          <td width="16%">
           <input type="text" name="condition(caseNo,like)" >
          </td>
          <td class="td1">
           补办状态：
          </td>

    ....

  <table>



JS :

function showHide(zoneId,obj){
     var zone=$(zoneId);
    if (zone.style.display=='none'){
     zone.style.display="block";
     obj.innerHTML=obj.innerHTML.replace("+","-");
     obj.innerHTML=obj.innerHTML.replace("显示查询条件","隐藏查询条件");
    }else{
     zone.style.display="none";
     obj.innerHTML=obj.innerHTML.replace("-","+");
     obj.innerHTML=obj.innerHTML.replace("隐藏查询条件","显示查询条件");
    }
   }