title: strpos() returning false, when needle is in haystack
body: <p>I was having trouble with a longer func i wrote, so i broke it down and it seems to be with the <code>strpos()</code> function.</p>
  
  <p>Even though the needle is clearly present in the haystack it returns false, for the life of me i cant work out why, oddly though if i change the needle to "sam" in becomes true.. any idea why ?</p>
  
  <pre><code>function verify_url($url) {
      if (strpos($url, "http://")) {
          return $url;
      } else {
          echo "error";
      }
  }
  
  
  $url = "http://sam.com";
  
  echo verify_url($url);
  </code></pre>