How to get this image "?" off of the header image.

[ericareid]

There is a broken image link on the header for e-stemacademy.org

Here is the info in my header.php:
</div>

<div id="header">

<div class="headerleft">

</div>


<div id="navbar">

I can;t figure out how and where this broken image link is so I can delete it. Can someone guide me on a few options to check so I can delete this on the site.

In Firefox it reads "Advertisement? and in Safari it's a "?"