Jquery dialog with <a>

Jquery dialog with <a>

Here's an example of what I'm trying to tie a dialog to: 
  1. <div id='dialog' title='Blog Post Viewer'></div>

  3. <a href='? $url_data ' onclick='return false' onmousedown=' run_modal ( \" $href \" , \" $url_data \" );'> $link_txt </a>
My goal is to be able to run "run_modal", and let it auto populate the dialog box with an ajax request.


When I run: 
  
    
   
  1. $(function() {
    2. 
   
  2.  $( "#dialog" ).dialog({
    3. 
   
  3.  autoOpen: false
    4. 
   
  4.  });
    5. 
   
  5. });
    6. 
   

    7. 
   
  7. function run_modal( href, url_data ) {
    8. 
   
  8.  $("#dialog").dialog("open");
    9. 
   
  9. // alert(href+"="+url_data);
    10. 
   
  10. }
    11. 
  

It comes up with this bug:
jquery-2.1.4.js:250 Uncaught Error: cannot call methods on dialog prior to initialization; attempted to call method 'open'


What am I doing wrong to trigger the dialog call?
Is there a way you would suggest changing the title, and body content on a single ajax call to the server?