fakefunc.js

var psuedoReusableFunction = function (param1, param2, param3, param4) {
  // do something with params 1 and 2
    DoSomething(param1);
    DoSomething(param2);
  // params 3 and 4 were added when your app changed but you didn't 
  // want to rewrite anything
    if (param3) {
     DoSomethingElse(param3);
    } 
  // ya da ya da  ...
};