<c:set var="abc" value="dfgd"/>
<table>
<c:if test="${ !('' eq abc) }">
<tr>
<td>1111</td>
<td>1111</td>
</tr>
</c:if>
<tr>
<td>aaa</td>
<td>123</td>
</tr>
</table>
function selectAll(str)
{
var all = document.getElementById("all").checked;
var cardIds = document.getElementsByName(str);
var n = cardIds.length;
if(all == true) {
for (var i = 0; i < n; i++)
cardIds[i].checked = true;
} else {
for (var i = 0; i < n; i++)
cardIds[i].checked = false;
}
}