title: Check if individual values entered by user are a number
body: <p>I know how to check if the value of a field is a number, and I know how to fire an event on keyup. What I do not know how to do it check if each individual entry(keyup) by the user is a number or not. I am not interested in its e.which representation. Just if the value entered is 0-9.</p>
  
  <p>I made a basic fiddle if you want to fill in the blanks. </p>
  
  <p><a href="http://jsfiddle.net/dan_vitch/M7dFy/" rel="nofollow">http://jsfiddle.net/dan_vitch/M7dFy/</a></p>