UIScrollView no response after clicking done butotn

[boyax]

The application consists of the scrollview with a lots of textfield.
Basically, I could scroll the scroll view..

I'm having problem when I clicked on the textfield for input, then, clicking done of the keyboard, keyboard hides..
but the view or the scroll view is not responding or freezes... I can't scroll..

Pls help me.

.m file:

#define SCROLLVIEW_CONTENT_HEIGHT 870
#define SCROLLVIEW_CONTENT_WIDTH  320

- (void)viewWillAppear:(BOOL)animated 
{
   [super viewWillAppear:animated];     
   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidShow:) name: UIKeyboardDidShowNotification object:nil];

   [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardDidHide:) name: UIKeyboardDidHideNotification object:nil];
     
   m_scrollView.contentSize = CGSizeMake(SCROLLVIEW_CONTENT_WIDTH, SCROLLVIEW_CONTENT_HEIGHT);     
   displayKeyboard = NO;
}

- (void)viewWillDisappear:(BOOL)animated 
{
   [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)keyboardDidShow: (NSNotification *)notif 
{
   if (displayKeyboard) {
     return;
   }

   NSDictionary* info = [notif userInfo];
   NSValue* aValue = [info objectForKey:UIKeyboardBoundsUserInfoKey];
   CGSize keyboardSize = [aValue CGRectValue].size;
   offset = m_scrollView.contentOffset;

   CGRect viewFrame = m_scrollView.frame;
   viewFrame.size.height -= keyboardSize.height;

   m_scrollView.frame = viewFrame;

   CGRect textFieldRect = [m_activeField frame];
   textFieldRect.origin.y += 10;

   [m_scrollView scrollRectToVisible: textFieldRect animated:YES];
   displayKeyboard = YES;
}

- (void) keyboardDidHide: (NSNotification *)notif 
{
   if (!displayKeyboard) {
     return; 
   }

   m_scrollView.frame = CGRectMake(0, 0, SCROLLVIEW_CONTENT_WIDTH, SCROLLVIEW_CONTENT_HEIGHT);     
   m_scrollView.contentOffset = offset;
   displayKeyboard = NO;     
}

#pragma mark * Textfield Delegate Methods
- (void)textFieldDidEndEditing:(UITextField *)textField
{
   if (textField == m_userNameField) 
   {
      //check username if exists
   }
   else if(textField == m_emailPrimaryField || textField == m_emailSecondaryField)  
   {
       //check input for email formatting
   }
}

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
   BOOL bReturn = YES;

   if (textField == m_userNameField || textField == m_firstNameField || textField == m_lastNameField) 
   {
      //text entry filter only alphanum inputs
   }     

   return bReturn;
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
   [textField resignFirstResponder];
   return YES;

}

-(BOOL) textFieldShouldBeginEditing:(UITextField*)textField 
{
   m_activeField = textField;
   return YES;
}

.h file

@interface NewUserViewController : UIViewController <UIScrollViewDelegate, UITextFieldDelegate>
{
   BOOL               displayKeyboard;
   CGPoint          offset;
   UITextField          *m_activeField;
   ....
}