A basic closure example. Also here: http://bost.ocks.org/mike/chart/

chart.js

function chart() {
  var width = 720, // default width
      height = 80; // default height

  function my() {
    // generate chart here, using `width` and `height`
  }

  my.width = function(value) {
    if (!arguments.length) return width;
    width = value;
    return my;
  };

  my.height = function(value) {
    if (!arguments.length) return height;
    height = value;
    return my;
  };

  return my;
}

closures.js

function SingleSelect() {
  // These variables won't get lost to the select view
  var x = 1;
  function self() {
    // initialization code goes here, if necessary
    // like some jquery setup of the select
  }
  
  self.change = funciton() {
    
  }
  
  return self;
}

var mySelect = SingleSelect();