Actually, this looks like a PHP problem.
echo "<img src=$source_image />";
Do you see a problem here? You closed the echo string -- and then have markup without a ?> -- that's gonna bomb on the server right there.
Really though you're using multiple echo to do the job of one.... that "col5" probably means some rubbish presentational HTML/CSS framework crap making life harder... I'm not sure all your classes are necessary or why you need quite so many DIV in there... and your lack of formatting is hiding that you also forgot to close a DIV. The colour syntax highlighter here ALONE is telling you there's something wrong. I'd also suggest switching to single-quotes and comma delimits instead of that goofy opening and closing PHP with multiple echo statements for NOTHING other than making the parser have to work harder. You are also trying to use the same ID more than once, and since your scripting is targeting by ID, that 'object' one (which is sending up warning flags here as something really craptastic since I smell flashtardery) is just going to fail... and I'm pretty sure you didn't want it INSIDE the previous panel_button. You also don't say "800px" on the height ATTRIBUTE, you say px on CSS properties. You want pixels in HTML, you omit the metric. Of course if you were to actually use HTML properly, you wouldn't be using that stupid STYLE attribute anywhere either.
WITHOUT fixing the classes for nothing, DIV for nothing, presentation in the markup, and just trying to make your broken methodology work, it would go something like this:
<div class="box col5">
<p>', $title, '</p>
<img src="', $source_image, " alt="DESCRIBE THIS IMAGE!!!" />
<div class="panel_button" style="display:visible;">
<img src="../images/expand.png" alt="expand"/>
<a href="#">', $item_title, '</a>
<div class="panel_button" id="hide_button" style="display:none;">
<img src="../images/collapse.png" alt="collapse" />
<!-- #hide_button.panel_button --></div>
<div class="panel_button" id="hide_button2" style="display:none;">
data="', $item_url, '"
style="overflow:auto; border:5px ridge blue"
<!-- #hideButton2.panel_button --></div>
<!-- .box.col5 --></div>';
I'd really have to see in action what you are trying to accomplish, but I think most of your scripting and a third your markup probably belongs on the cutting room floor -- but at least the above will get your PHP outputting something. ('cause what you have right now WON'T!)
.. that said, it looks like you either have a ton of jQuery for nothing, or JQ doing CSS' job. Don't know what that mess of scripting is supposed to do, but it doesn't look good.
Oh, and @\.\ -- you might want to ease up on people about where they post things, particularly if you're not even going to LOOK at the code that has NOTHING to do with what you said, but is in fact full of bugs and problems to be fixed elsewhere! This is like the tenth thread I've seen you do this to someone where your complaint has had jack **** to do with the person's problem or even where the post belongs. I might be a colossal jackass to people, but at least when I do so I'm trying to help.