I'm using angular to develop a web app and I'm trying to use a function's `.bind` method to assign the this value on a method of one of my controllers. It looks like this:

```
var welcomeCtrl = function (userManager) {
  this.partnerName = userManager.getName('partner');
  this.yourName = userManager.getName('you');
  this.beginScan = false;
  var self = this;
};

welcomeCtrl.prototype.scanThumb = function (callback) {
  function doScan() {
    alert(this);
    alert(this.beginScan);
    this.finishedScanning = callback;
    this.beginScan = true;
  }

  doScan.bind(welcomeCtrl)();

};

```

So what happens is that a directive passes the scanThumb method to a service which executes it, which should then trigger another directive waiting for `this.beginScan` to be true.

Since its the service that calls the method and it is not called from the `welcomCtrl` class, I need to bind `this` back to `welcomeCtrl` so I use `.bind` and pass in `welcomeCtrl`

This should work, when I do `alert(this)` the welcomeCtrl function definition alerts fine, but when I do `alert(this.beginScan)` I get `Undefined`

Am I not understanding how the .bind method works in this circumstance?