List Administrators with css/javascript hover

Hello,

I am trying do something just a little out of my range. Hopefully it is very easy for one of you guys and with a little help I can solve it 🙂

I have the following code to list my administrators, works fine:

<ul>
<?php
    $blogusers = get_users('blog_id=1&orderby=nicename&role=administrator');
    foreach ($blogusers as $user) {
        echo '<li>' . $user->display_name . '</a>' . '</li>';
    }
?>
</ul>

now I want to do the following. When a user hovers over an listed user there has to popup some information. For the popping up I have the following code (which works of course with a javascript, and I have this also working):

<a
   onmouseover="ShowContent('popup'); return true;"
   onmouseout="HideContent('popup'); return true;"
   href="javascript:ShowContent('popup')">
[show on mouseover, hide on mouseout]
</a>
<div id="popup">
	Content goes here.
</div>

Now I want to combine the two. And the trouble starts here for me. Because the ‘ before and after the word popup destroys it. I was thinking something like the following code:

<ul>
<?php
    $blogusers = get_users('blog_id=1&orderby=nicename&role=administrator');
    foreach ($blogusers as $user) {
        echo '
<li>' . '<a
   onmouseover="ShowContent('popup'); return true;"
   onmouseout="HideContent('popup'); return true;"
   href="javascript:ShowContent('popup')">' . $user->display_name . '</a> <div id="popup">
	Content goes here.
</div>' . '</li>
';
    }
?>
</ul>

but this is not allowed. Does somebody knows the answer?