 <p>All your optionals need to be unwrapped. So <code>lvt</code> should become <code>lvt!</code></p> <p><strong>Word of Caution</strong> Unwrapping an optional which doesn't have a value will thrown an exception. So it might be a good idea to make sure your lvt isn't nil. </p> <pre><code>if (lvt != nil) </code></pre>