Use window.open
to popup new window
echo "<tr bgcolor='#EBEBE6'>
<td width='5'> </td>
<td>".$rows['Date']."</td>
<td>".$rows['Payment_ID']."</td>
<td>".$rows['Staff_ID']."</td>
<td>".$rows['Amound']."</td>
<td><a href='#' onclick='window.open("you url here","","width=200,height=100");'>".$rows['Comments']."</td>
</tr>";