title: Slight Issue with usort
body: <p>Having a slight issue getting my array to sory by <code>Distance</code> properly.  I though that using <code>usort</code> would do the trick, but I am apparently mistaken?</p>
  <h1>usort</h1>
  <pre><code>usort($return, function($a, $b){
      $t1 = $a['Distance'];
      $t2 = $b['Distance'];
      return $t1 - $t2;
  }); 
  </code></pre>
  <p><code>$return</code> produces:</p>
  <pre><code>Array
  (
  [0] =&gt; Array
      (
          [ZipCode] =&gt; 06096
          [Distance] =&gt; 0
      )
  
  [1] =&gt; Array
      (
          [ZipCode] =&gt; 06096
          [Distance] =&gt; 0
      )
  
  [2] =&gt; Array
      (
          [ZipCode] =&gt; 06026
          [Distance] =&gt; 3.16
      )
  
  [3] =&gt; Array
      (
          [ZipCode] =&gt; 06080
          [Distance] =&gt; 4.14
      )
  
  [4] =&gt; Array
      (
          [ZipCode] =&gt; 06080
          [Distance] =&gt; 4.14
      )
  
  [5] =&gt; Array
      (
          [ZipCode] =&gt; 06078
          [Distance] =&gt; 4.14
      )
  
  [6] =&gt; Array
      (
          [ZipCode] =&gt; 06064
          [Distance] =&gt; 3.6
      )
  
  [7] =&gt; Array
      (
          [ZipCode] =&gt; 06028
          [Distance] =&gt; 3.6
      )
  
  [8] =&gt; Array
      (
          [ZipCode] =&gt; 06028
          [Distance] =&gt; 3.6
      )
  
  [9] =&gt; Array
      (
          [ZipCode] =&gt; 06006
          [Distance] =&gt; 4.83
      )
  
  [10] =&gt; Array
      (
          [ZipCode] =&gt; 06095
          [Distance] =&gt; 4.83
      )
  
  [11] =&gt; Array
      (
          [ZipCode] =&gt; 06095
          [Distance] =&gt; 4.83
      )
  
  [12] =&gt; Array
      (
          [ZipCode] =&gt; 06006
          [Distance] =&gt; 4.83
      )
  
  )
  </code></pre>