Show and Hide view in xCode
- (IBAction) slideDrawer: (id) sender;

- (IBAction) slideDrawer: (id) sender;
{
  CGFloat newX;
  if (drawerIsShowing)
    newX = kOffscreenX;
  else
    newX = kVisibleX;
  [UIView animateWithDuration: .25
  animations:
  ^{
    CGRect drawerFrame = drawerView.frame;
    drawerFrame.origin.x = newX;
    drawerView.frame = drawerFrame;
  }
drawerIsShowing = !drawerIsShowing;
}