Xcode 4.2中的内存泄漏

Question

  

可能重复：
  My program has a memory leak

-(IBAction)pushAbout  
{  
    UIAlertView *alert =[[UIAlertView alloc]initWithTitle:@"About" message:@"Created by Alfred"   delegate:nil      
cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
    [alert show];

}

它告诉我分配的对象可能存在泄漏