Try this
<table border="1">
<tr>
<th><input type="checkbox" id="selectall" onchange="chkall()"/></th>
<th>Select</th>
<th>All</th>
</tr>
<tr>
<td align="center"><input type="checkbox" id="1" value="1"/></td>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td align="center"><input type="checkbox" id="2" value="2"/></td>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td align="center"><input type="checkbox" id="3" value="3"/></td>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td align="center"><input type="checkbox" id="4" value="4"/></td>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td align="center"><input type="checkbox" id="5" value="5"/></td>
<td>1</td>
<td>2</td>
</tr>
</table>
function chkall() {
var sall = document.getElementById("selectall");
var il = document.getElementsByTagName("input");
if (sall.checked) {
for (var i = 0; i < il.length; i++) {
il(i).checked = true;
}
}
else
{
for (var i = 0; i < il.length; i++) {
il(i).checked = false;
}
}
}
Thanks,
--RG