checkbox validation?

Hello. How can I allow only one checkbox selected per row??
<table><tr>
<td width=8%>$itemid</td>
<td width=6% id=\"tdID1\" ><input type='checkbox' ONCLICK=\"highlightRow(this, 'lime');\" class='normal2' name='edit[]' value='$line[id]' ></td>
<td width=4% id=\"tdID1\" ><input type='checkbox' ONCLICK=\"highlightRow(this, 'red');\" class='normal2' name='delete[]' value='$line[id]' ></td>
<td width=4% id=\"tdID1\" ><input type='checkbox' ONCLICK=\"highlightRow(this, 'blue');\" class='normal2' name='request[]' value='$line[id]' ></td>

</tr></table>

http://www.vicsjavascripts.org.uk/FormCompendium/FormCompendium.htm#f6