Can you use if statements for css classes?

Question

I'm trying to make a table field change color depending on what info the field is pulling from the database.  Here is my code:
<table>
<?php do { ?>
      <tr>
        <td><input name="hiddenField" type="hidden" id="hiddenField" value="<?php echo $row_getSystems['path_id']; ?>" />
          <strong><?php echo $row_getSystems['system']; ?></strong></td>
        <td><?php echo $row_getSystems['jumps']; ?></td>
<?php
  if ($row_getSystems['security'] < 0.5) {
  ?>
  <td class="alert"><?php echo $row_getSystems['security']; ?></td> <? ;}
  elseif ($row_getSystems['security'] < 0.7)  {
  ?>
        <td class="noalert"><?php echo $row_getSystems['security']; ?></td> <? ;}
  else {
  ?>
  <td class="good"><?php echo $row_getSystems['security']; ?></td> <? ;} ?>
        <td><?php echo $row_getSystems['belts']; ?></td>
        <td><?php echo $row_getSystems['station']; ?></td>
        <td><?php echo $row_getSystems['deadend']; ?></td>
        </tr>
      <?php } while ($row_getSystems = mysql_fetch_assoc($getSystems)); ?>
  </table>
I added the spaces to make the part I wrote stand out better.
When I try to view it live - it says:
Parse error: syntax error, unexpected end of file in C:\xampp\htdocs\mining\systems.php on line 101
Any ideas on how to do this?  Cause clearly, I'm not doing it correctly. 
Thanks!

Answer 1

Nevermind, I figured out how to do it.  Here is the correct code.  I presume this is the best way.  Hopefully. 
<table>
  <?php do { ?>
      <tr>
        <td><input name="hiddenField" type="hidden" id="hiddenField" value="<?php echo $row_getSystems['path_id']; ?>" />
          <strong><?php echo $row_getSystems['system']; ?></strong></td>
        <td><?php echo $row_getSystems['jumps']; ?></td>
        <!-- Table Background Changes -->
                    <td style=" color: #fff;
                    <?php
                    if ($row_getSystems['security'] < 0.5) {
                    echo "background-color: #C00"; }
                    elseif  ($row_getSystems['security'] < 0.7) {
                    echo "background-color: #F90"; }
                    else {
                    echo "background-color: #060";
                    ?>
        ">
                      <strong><?php echo $row_getSystems['security']; ?></strong></td>
        <!-- End of Changes -->
        <td><?php echo $row_getSystems['belts']; ?></td>
        <td><?php echo $row_getSystems['station']; ?></td>
        <td><?php echo $row_getSystems['deadend']; ?></td>
        </tr>
      <?php } while ($row_getSystems = mysql_fetch_assoc($getSystems)); ?>
  </table>