Create a "Popup" jQuery Plugin

Create a "Popup" jQuery Plugin

I am looking for creating my own popup dialog jQuery plugin  (I know this looks stupid, but please, go ahead reading) . I have read more about creating plugin in jQuery in their documentation and I've already written something but I realized that I don't know my directions. I mean should I have something like:
  1. <div class="popup" id="myWindow">This is some of its contents</div>
  2. <script>
  3. $("#myWindow").popup({/* options */}, { ok: "Ok", cancel: "Cancel" /* buttons */ });
  4. </script>
or should I go for somethings else? Below is somethings I've written, but I don't have an implementation yet:
  1. (function( $ ) {        
  2.     $.fn.popup = function( options )
  3.     {
  4.         var opts = $.extend({}, $.fn.popup.defaults, options);                          
  5.     };      
  6.     $.fn.popup.defaults = {
  7.         width: "350px",
  8.         backgroundColor: "#ffffff"  
  9.     };          
  10. }(jQuery));

I don't really need somebody to write my entire code, but I want some directions and references. Also, if you have the time to help with some snippets (because I am not an advanced jQuery user/programmer), I will be grateful.

So, can anybody help me?