title: How to use NSNotification
body: <p>In my application there is two viewControllers as <code>FirstViewController</code> and <code>DetailViewController</code>. 
  When tap on a table cell, it navigate to <code>DetailViewController</code>. In <code>DetailViewController</code>, I want to edit and reload the <code>FirstViewController</code>'s table view </p>
  
  <p>How can I use <code>NSNotification</code> for this problem?</p>
  
  <p>Here's the method I want to implement <code>NSNotification</code> stuff</p>
  
  <pre><code>-(IBAction) save{
  strSelectedText=theTextField.text;
  
  [NSNotificationCenter defaultCenter];
  NSNotification* notification = [NSNotification notificationWithName:@"MyNotification" object:self];
  [[NSNotificationCenter defaultCenter] postNotification:notification];  
  
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector (objFirstViewController) name:@"MyNotification" object:nil];
  
  
  
  [self.navigationController popViewControllerAnimated:YES];
  }
  </code></pre>