Javascript Singleton Object

Have you come across a problem where you have to create an object that can only be initialized once and you want to reuse that object throughout your whole application? Well maybe you haven't but I actually came across that problem the other day and here's the solution for it:

function singleton() {
 var instance = (function() {
   var privateVar;

   function privateMethod () {
     // ...
   }

   return { // public interface
     publicMethod1: function () {
         // private members can be accessed here
      },
     publicMethod2: function () {
       // ...
     }
   };
 })();

 singleton = function () { // re-define the function for subsequent calls
   return instance;
 };

 return singleton(); // call the new function
}

Solution given by CMS on Stack overflow(http://stackoverflow.com/questions/1895635/javascript-singleton-question)