design patterns - JavaScript Independent Modules -

i have several modules in application , global variables. 1 module may require methods other modules work , global variables.

how can organise code modules won't use methods other modules or global variables?

//global variables needed in both of modules. var a, b;  //video module var video = (function() {      //requires method user module:     if(user.has_liked_video()) {         //do smth.     }      //requires global variables      return {} })();  //user module var user = (function() {      //requires method video module:     if(video.exists()) {         //do smth.     }      //requires global variables      return {} })();