title: Key input won't work in Unity
body: <p>I have been following a pong tutorial, but I have a problem.</p>
  
  <p>The rackets are not moving when you press the arrow.</p>
  
  <pre><code>using UnityEngine;
  using System.Collections;
  
  public class MoveRacket : MonoBehaviour
  {
      // up and down keys (to be set in the Inspector)
      public KeyCode up;
      public KeyCode down;
  
      void FixedUpdate()
      {
          // up key pressed?
          if (Input.GetKey(up))
          {
              transform.Translate(new Vector2(0.0f, 0.1f));
          }
  
          // down key pressed?
          if (Input.GetKey(down))
          {
              transform.Translate(new Vector2(0.0f, -0.1f));
          }
      }
  }
  </code></pre>
  
  <p>And I assigned the images a key in the inspector.</p>