[Plugin: XML Google Maps] Moving the closing DIV tag

Currently, when I embed a map in a post, this is what I get:

<div style="text-align: 0;"><iframe src="URL" style="border: 0px; width: 750px; height: 400px;" name="Google_KML_Maps" frameborder="0"></iframe></div>
<p><a href="URL">Download KMZ-file.</a></p>

The WordPress theme I’m using has a DIV class “captionfull” that styles an alinea if it’s within the DIV, so I’d like to add the class and move the closing DIV tag like this:

<div class="captionfull" style="text-align: 0;"><iframe src="URL" style="border: 0px; width: 750px; height: 400px;" name="Google_KML_Maps" frameborder="0"></iframe>
<p><a href="URL">Download KMZ-file.</a></p>
</div>

I found this line in xmlgooglemaps.php:

$content = str_replace($found[0][$i],'<div style="text-align: '.$params->align.';"><iframe src="'.get_option('siteurl').'/wp-content/plugins/xml-google-maps/xmlgooglemaps_show.php?kmlid='.$kmlid.'" style="border: 0px; width: '.$params->width.'px; height: '.$params->height.'px;" name="Google_KML_Maps" frameborder="0"></iframe></div>'.$displayurl,$content);

Adding the class is easy, but I can’t figure out where I have to put the closing DIV tag. I tried placing it behind $content normally, between ” and with a comma (,) after $content, but everything results in the page being unable to load. What is the correct way to edit the code?

Thanks in advance.