title: Trying to get setEditable to false but get an Error
body: <p>I'm having trouble with a part in my code:</p>
  
  <pre><code>public class NumbersJava extends Applet{
  TextField tF1 = new TextField(3);
  tF1.setEditable(false);
  </code></pre>
  
  <p>The error shows up as:
  <a href="https://i.stack.imgur.com/4lxKW.png" rel="nofollow noreferrer">The error.</a></p>
  
  <p>Why does it come up with this error?
  What can I do to fix this?</p>
  
  <p>And yes further in the code I have implemented a:</p>
  
  <pre><code>public void init(){
  add(tF1);
  </code></pre>