title: Checking whether input is a number or a character
body: <p>I am trying a guessing game. Guessing between 0 and 5. I know most of my problems could be sorted using the numeric keypad for the data input, but I am trying to learn as much as I can, so I am trying to think of all the incorrect errors that could happen with a full keyboard and give the relevant err messages.</p>
  
  <p>I think I have covered all, the only one I can´t get is giving an err when a character rather than a number is input. Can someone help. My code is:</p>
  
  <p><a href="http://i.stack.imgur.com/amyFd.png" rel="nofollow">enter image description here</a></p>
  
  <p>Thanks</p>