Getting attribute val inside a UI callback

Getting attribute val inside a UI callback

I want the get the attribute value of my "event_id" attribute defined in my div inside the open portion of the dialog jquery function but I don't know how to get that information. The reason I need it is b/c ultimately I'm calling another JS function inside the open: of the dialog that requires this value. Thanks in advance.

I have the following:

HTML:

<div id="dialog" title="Dialog Title">                                                  
  TEST                      
</div> 

<p><a href="#" id="dialog_link" event_id="111181">Open Dialog</a></p>

script:
          
jQuery(document).ready(function($) {                                                    
                                                                                        
    // Dialog                                                                           
    $('#dialog').dialog({                                                               
        modal: true,                                                                    
        autoOpen: false,                                                                
        width: 600,                                                                     
        height: 400,                                                                    
        open: function(event,ui) {                                                      
         var id = $(this).attr("event_id");                                             
          alert(this.event_id);                              // <-- value "undefined"                            
        },                                                                              
        buttons: {                                                                      
            "Ok": function() {                                                          
                $(this).dialog("close");                                                
            },                                                                          
            "Cancel": function() {                                                      
                $(this).dialog("close");                                                
            }                                                                           
        }                                                                               
                                                                                        
    });                                                                                 
                                                                                        
    // Dialog Links                                                                     
                                                                                        
    $('#dialog_link').click(function(){                                                 
        $('#dialog').dialog('open');                                                    
        return false;                                                                   
    });                                                                      
}