title: How to use navCtrl.push() using a variable that contains a class name?
body: <p>I'm working with Visual Studio Code on Ionic 3 and AngularJS/Typescript.
  I use this.navCtrl.push() to jump to another page.
  I have two classes/pages i need to jump to, they are called "level1" and "level2". when i use</p>
  
  <pre><code>this.navCtrl.push(level2)
  </code></pre>
  
  <p>it works fine!
  however when i use a variable:</p>
  
  <pre><code>levelNbr: any;
  
  if(value == null)
  {
     this.levelNbr = "level1"
  }
  else
  {
     this.levelNbr = "level2"
  }
  
  this.navCtrl.push(this.levelNbr)
  </code></pre>
  
  <p>I get an error saying: </p>
  
  <blockquote>
    <p>Uncaught (in promise): invalid link: level2</p>
  </blockquote>
  
  <p>This means its actually reading level2. however its not opening the page.
  How is it possible to open/push the page using a variable?</p>
  
  <p>Thank you</p>
  
  <p>Adding used code:</p>
  
  <pre><code>import { level1 } from './../levels/levels';
  import { level2 } from './../levels/levels';
  //all classes are in one file called levels
  </code></pre>
  
  <p>in the app.modules.ts they are declared as well.</p>