Unique radio name in php while loop

Unique radio name in php while loop

Well, I've following Php code which generate a table with radio button so
that user can select only one radio button in EVERY row. But to select
only one radio button in Every row it's must be a unique name in EVERY
row, Right ? But I can't get any idea how do i set a unique name in while
loop. Can you guys give me any idea or solutions ?
Php code:
$action = htmlspecialchars($_SERVER['PHP_SELF'])."?class=$class_from";
echo "<form method='post' action='$action' name='attendence'/>";
echo "<table width='100%' cellpadding='0' cellspacing='0' border='0'>";
echo "<tr>";
echo "<td class='tdhead' valign='top' width='200'><b>Student Name</b></td>";
echo "<td class='tdhead' valign='top' width='250'><b>Roll No</b>
</td>";
echo "<td class='tdhead' valign='top' width='250'><b>Class Name</b>
</td>";
echo "<td class='tdhead' valign='top' width='200'><b>Present / Not
present</b>
</td>";
echo "<td class='tdhead' valign='top' width='200'>Check All <input type=
'checkbox'
onclick='checkAll(this)' /></td>";
echo "</tr>";
while($res2 = mysql_fetch_array($sql2))
{
$sname = inputvalid($res2['sname']);
$roll = inputvalid($res2['roll']);
$class = inputvalid($res2['class']);
echo "<tr>";
echo "<td class='tdhead2' valign='top'>$sname</td>";
echo "<td class='tdhead2' valign='top'>$roll</td>";
echo "<td class='tdhead2' valign='top'>$class</td>";
echo "<td class='tdhead2' valign='top'>
<input type='radio' name='ch[]' value='1' />&nbsp;<input type='radio'
name='ch[]'
value='1' />
</td>";
echo "<td class='tdhead2' valign='top'>&nbsp;</td>";
echo "</tr>";
}
echo "<tr>";
echo "<td class='tdhead2'>&nbsp;</td>";
echo "<td class='tdhead2'>&nbsp;</td>";
echo "<td class='tdhead2'>&nbsp;</td>";
echo "<td class='tdhead2'>&nbsp;</td>";
echo "<td class='tdhead2'><input type='submit' value='Record' name='Submit'
class='submit' /></td>";
echo "</tr>";
echo "</table>";
echo "</form>";
Thanks for your help.