//include jquery
  <link rel="stylesheet" href="http://code.jquery.com/ui/1.11.4/themes/smoothness/jquery-ui.css">
  <script src="http://code.jquery.com/jquery-1.10.2.js"></script>
  <script src="http://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>

//javascript
<script>
 $(function() {
    $( "#dialog" ).dialog({
      autoOpen: false,
      show: {
        effect: "blind",
        duration: 1000
      },
      hide: {
        effect: "explode",
        duration: 1000
      }
    });

    $( "#dialog_link" ).click(function() {
      $( "#dialog" ).dialog( "open" );
    });
  });
</script>

//echoed php
<div id='dialog' title='Message from ".$from_user." on ".dateConvert2($notify['date'])."'>
    <p>".bb_parse($notify['comment'])."</p>
</div>
<a id='dialog_link' href='notifications.php?id=".$notify['id']."'>CLICK TO SEE MESSAGE</a>