title: using - if( isNaN( ) ) ) to find an replace
body: <p>I've got a little calculator that I want to configure CSS Margin Shorthand to %</p>
  
  <p>I'm currently getting the user to input the numbers in a form on which I then seperate each number and 'do the maths' to it.</p>
  
  <p>I want it to ignore any NaN when the user uses CSS shorthand.</p>
  
  <p>I've currently got this -</p>
  
  <pre><code>  if( isNaN( parseInt(margins || paddings ) ) )
         alert(" Please re-enter your age.");
  </code></pre>
  
  <p>which works but I want to change the "alert" bit to just ignore/replace the NaN with nothing.</p>
  
  <p>Any ideas?</p>
  
  <p>here's a link to my JSFiddle - <a href="http://jsfiddle.net/sturobson/reCjA/8/" rel="nofollow">http://jsfiddle.net/sturobson/reCjA/8/</a></p>
  
  <p>I don't want the NaN's to appear if the user hasn't submitted any numbers</p>