title: How to update a UI label from a non UI thread in iOS
body: <p>I am new to iOS development, I have plain objective -c class "MoneyTimer.m" for running timer, from there i want to update the  an UI label with the changing value of timer. 
  I want to Know how to access the UI element from non UI thread ? I am Using Xcode 4.2 and storyboarding. </p>
  
  <p>In blackberry simply by getting the event lock one can update the UI's from non UI thread.</p>
  
  <pre><code>//this the code from MyTimerClass
  
   {...
      if(nsTimerUp == nil){
  
          nsTimerUp = [NSTimer scheduledTimerWithTimeInterval: 1.0 target:self selector:@selector(countUpH) userInfo:nil repeats: YES];
   ...}
  
  (void) countUpH {
  
  sumUp = sumUp + rateInSecH;
   **//from here i want to update the UI label **
  ...
  }
  </code></pre>