Made customizable 404 page have a {STANDARD404} variable available to allow embedding the "default" 404 content.
<!-- VAR sidebar_button --><li><a href="javascript:void(0)" {FLAGS}>{TEXT}</a></li>
<!-- ENDVAR sidebar_button -->
<!-- VAR sidebar_raw --><li><span style="text-align: center;">{HTML}</span></li>
<!-- ENDVAR sidebar_raw -->
<!-- VAR sidebar_top -->
<div class="recttop">
<table border="0" width="100%" cellspacing="0" cellpadding="0" style="font-size: 1px;">
<tr>
<td style="margin: 0; padding: 0; height: 12px;"> <img alt=" " src="{SCRIPTPATH}/themes/oxygen/images/{STYLE_ID}/border-menu-l.gif" width="12" height="12" /> </td>
<td style="margin: 0; padding: 0; height: 12px;" class="recttoptop"></td>
<td style="margin: 0; padding: 0; height: 12px;"> <img alt=" " src="{SCRIPTPATH}/themes/oxygen/images/{STYLE_ID}/border-menu-r.gif" width="12" height="12" /> </td>
</tr>
</table>
</div>
<!-- ENDVAR sidebar_top -->
<!-- VAR sidebar_section -->
<div class="dbx-box">
<div class="dbx-handle">
{ADMIN_START}
{TITLE}
{ADMIN_END}
</div>
<div class="dbx-content">
<ul>
{CONTENT}
</ul>
</div>
</div>
<!-- ENDVAR sidebar_section -->
<!-- VAR sidebar_section_raw -->
<div class="dbx-box">
<div class="dbx-handle">
{ADMIN_START}
{TITLE}
{ADMIN_END}
</div>
<div class="dbx-content dbx-content2">
<ul><li>
{CONTENT}
</li></ul>
</div>
</div>
<!-- ENDVAR sidebar_section_raw -->
<!-- VAR sidebar_bottom -->
<div class="rectbot">
<table border="0" width="100%" cellspacing="0" cellpadding="0" style="font-size: 1px;">
<tr>
<td style="margin: 0; padding: 0; height: 12px;"> <img alt=" " src="{SCRIPTPATH}/themes/oxygen/images/{STYLE_ID}/border-bl.gif" width="12" height="12" /> </td>
<td style="margin: 0; padding: 0; height: 12px;" class="rectbottop"></td>
<td style="margin: 0; padding: 0; height: 12px;"> <img alt=" " src="{SCRIPTPATH}/themes/oxygen/images/{STYLE_ID}/border-br.gif" width="12" height="12" /> </td>
</tr>
</table>
</div>
<!-- ENDVAR sidebar_bottom -->