That was a typo in my comment, oops! Here is the code I use which gives me a 500 error:
public function manage(){
$mysidia = Registry::get("mysidia");
$aid = $this->getField("aid")->getValue();
$name = $this->getField("name")->getValue();
$image = $this->getField("image");
$document = $this->document;
$document->setTitle("Managing {$name}");
$document->add(new Comment("<div style='background:{$adopt->adoptbackground} no-repeat;vertical-align:bottom;text-align:center;width:100px;height:400px'><img src='{$adopt->getImage()}'/></div><br><br>This page allows you to manage {$name}. Click on an option below to change settings.<br> "));
Here is what happens with the same code except I removed the "img src" tag" (I gave it a height and width to show the div was being created and modified):
Thanks for the help guys.