Thread and NSTimer
<p>I am making an application that has a timer. I count the minutes and seconds from a given time down to 0. When this happen I launch an alertview.</p>

<p>My structure is this:</p>

<p>Mainthread method allocate a new thread and initialize it.
The entrypoint(method) for the thread has a timer which invokes a method for calculating time left, and if the time is up, displays an alertview. </p>

<p>However, is this correct? Because now I am updating GUI from another thread than the main...and that is bad right? And I am also displaying an alertview from this thread. </p>

<p>I thought of making another method that encapsulate all the logic for updating and displaying the alertview and in the method that the nstimer invokes use the performSelectorInMainThread, however is this correct?</p>

<p>Thanks for your time.</p>
