Static body for resizing (How to keep the body from sliding and moving when resizing)

[bjmhistory]

I place my custom header in the tpl_header.php file after the <div id="headerWrapper"> and it appears as follows:

<div id="headerWrapper">
<?php
include ("http://www.historicalpreservation.org/store/index_header.html");
?>
<!--bof-navigation display-->
<div id="navMainWrapper">
<div id="navMain">


This seems to have done the trick, however, it appears my headerwrapper margin needs to be adjusted.

This must be a stylesheet issue.