选择只选择默认值的选项

下面是我的html &php代码。我不知道哪里出了问题。但无论我选择哪个选项，它都是默认的。即使我选择header3，它也会变成header默认值。有人能帮帮我吗?由于

<tr>
<td>Select Header</td>
<td>
  <select name='meta[choose_header]'>
    <option value='header_default' <?=$post->get_meta("choose_header") == "header_default" ? "selected" : "" ?> >Header Default</option>
    <option value='header1' <?=$post->get_meta("choose_header") == "header1" ? "selected" : "" ?> >Header 1</option>
    <option value='header2' <?=$post->get_meta("choose_header") == "header2" ? "selected" : "" ?> >Header 2</option>
    <option value='header3' <?=$post->get_meta("choose_header") == "header3" ? "selected" : "" ?> >Header 3</option>
    <option value='header4' <?=$post->get_meta("choose_header") == "header4" ? "selected" : "" ?> >Header 4</option>
    <option value='header5' <?=$post->get_meta("choose_header") == "header5" ? "selected" : "" ?> >Header 5</option>
  </select>
</td>
</tr>

  <?php if ($post->get_meta("choose_header") == "header1"){ ?>
    <p><?=$theme->get_option("address1")?></p>
    <?} elseif ($post->get_meta("choose_header") == "header2") { ?>
    <p><?=$theme->get_option("address2")?></p>
  <?} elseif ($post->get_meta("choose_header") == "header3") { ?>
    <p><?=$theme->get_option("address3")?></p>
    <?} elseif ($post->get_meta("choose_header") == "header4") { ?>
    <p><?=$theme->get_option("address4")?></p>
  <?} elseif ($post->get_meta("choose_header") == "header5") { ?>
    <p><?=$theme->get_option("contact_address5")?></p>
  <?} elseif ($post->get_meta("choose_header") == "default") { ?>
    <p><?=$theme->get_option("address_default")?></p>
  <?}
  else{?>
    <p><?=$theme->get_option("address_default")?></p>
  <?}?>
</div>