AngularJS Form Validation - Disable Submit / Confirm Password Custom Directive

Creates a "UserValidation" module with validation directive to make sure passwords match. http://thomporter.com

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.2.2/css/bootstrap-combined.min.css">
<div ng-app="">
  <form name="myForm">
    <label for="username">Username</label>
    <input type="text" id="username" name="username" ng-model="formData.username" required />
    <span ng-show="myForm.username.$error.required && myForm.username.$dirty">Required</span>


    <label for="password">Password</label>
    <input type="password" id="password" name="password" ng-model="formData.password" required />
    <span ng-show="myForm.password.$error.required && myForm.password.$dirty">Required</span>
    <br />

    <button type="submit" class="btn" ng-disabled="myForm.$invalid">Submit</button>
  </form>
</div>