title: options variable is undefined
body: <p>I'm creating my first plugin and having some challenges.  I define a couple global variables: defaults and options.  I'm following the pattern for a plugin like so:</p>
  
  <pre><code> (function ( $ ) {
     var defaults;
     var options;
  
     $.fn.button_carousel = function(options){
      console.debug("initializing button carousel");
  
      defaults = {
        days_in_month: 0,
        starting_day: 0,
        days_with_appointments: null,
        btnAppointmentFontColor: "#556b2f"          
      };
  
  
  
      options = $.extend({}, defaults, options);
  
      console.debug("options: days_in_month: " + options.days_in_month +
                  "options: staring_day: " + options.starting_day +
                  "options: days_with_appointments: " + options.days_with_appointments);
      ...
  
      HighlightDays();
  
   return this.each(function(){
       console.log(options);
    });     
  };
  
   function HighlightDays()
   {
      if(options.days_with_appointments != undefined &amp;&amp; options.days_with_appointments != null)
      {
         ...
      }
   }
  }( jQuery ));
  </code></pre>
  
  <p>Check out the debug statement.  It prints out the values of each property as expected. However, when I call function HightlightDays(), the condition of the if statement throws up an error stating options variable is undefined.  How can that be? I declare it as a global variable so it can be accessed everywhere.  Please explain.</p>