title: How do I change timing for NSTimer?
body: <p>I have the following code:</p>
  
  <pre><code>timer = [[NSTimer scheduledTimerWithTimeInterval:0.50 target:self selector:@selector(onTimer) userInfo:nil repeats:YES] retain];    
  
  -(void) onTimer 
  {
  }
  </code></pre>
  
  <p>After every 0.50 seconds the <code>OnTimer</code> method is called.</p>
  
  <p>But now I want to increment the time-interval.</p>
  
  <p>That means:</p>
  
  <pre><code>OnTimer calls after 0.55
  OnTimer calls after 0.60
  OnTimer calls after 0.65
  OnTimer calls after 0.70
  OnTimer calls after 0.75
  &amp; so on.
  </code></pre>
  
  <p>Is there any solution for this?? I have tried lot but its not working.</p>