title: Math operation when operator is stored in a string
body: <p>Have two variables both containing integers:</p>
  
  <pre><code>var input;
  var value;
  </code></pre>
  
  <p>Need to perform arithmetic on them but have operator stored in variable:</p>
  
  <pre><code>var operator;
  </code></pre>
  
  <p>How do i perform the math?<br>
  i.e. document.write(input operator value);</p>
  
  <p>Thank You</p>