Singular layout problem

Hi folks,

I’m trying to make the content the full width of the site if there is no submenu. If there are child links I’d like to indent the primary div and float the submenu on the left hand side of the page.

Here is my code to determine if theres a submenu:

<?php if ($children) { ?>
<div id="primary" >
 <?php } else{?>
<div id="primary" class="singular">
 <?php  }?>

I’ve tried setting the width of primary, content and main to 100%, but there is always a indent, can anyone please help me code this correctly?

http://tinylink.net/96798

Thankyou