How to update data to Mobile Services - iOS / iPhone (Windows Azure)

-(void)updateItem:(NSMutableDictionary *)mutable completion:(QSCompletionBlock)completion
{
    
    // Update the item in the TodoItem table and remove from the items array on completion
    [self.table update:mutable completion:^(NSDictionary *item, NSError *error) {
        
        [self logErrorIfNotNil:error];

        // Let the caller know that we have finished
        completion();
    }];
}

- (IBAction)btnSave:(id)sender {

    // Find item that was commited for editing (update)
    NSDictionary *item = [self.memberService.items objectAtIndex:0];
    
    NSMutableArray *mutableItems = (NSMutableArray *) upItems;
    
    // Set the item to be complete (we need a mutable copy)
    NSMutableDictionary *mutable = [item mutableCopy];
    [mutable setObject:txtUsername.text forKey:@"username"];
    [mutable setObject:txtPassword.text forKey:@"password"];
    [mutable setObject:txtName.text forKey:@"name"];
    [mutable setObject:txtEmail.text forKey:@"email"];
    [mutable setObject:txtTel.text forKey:@"tel"];
    
    // Replace the original in the items array
    NSUInteger index = [upItems indexOfObjectIdenticalTo:item];
    [mutableItems replaceObjectAtIndex:index withObject:mutable];

    // Ask the todoService to set the item's complete value to YES, and remove the row if successful
    [self.memberService updateItem:mutable completion:^(NSUInteger index)
     {
         UIAlertView *av =
         [[UIAlertView alloc]
          initWithTitle:@"Update Data"
          message:@"Update Data Successfully."
          delegate: self
          cancelButtonTitle:@"OK"
          otherButtonTitles:nil
          ];
         [av show];
         
          //ViewController *view2 = [[[ViewController alloc] initWithNibName:nil bundle:nil] autorelease];
          //[self presentViewController:view2 animated:YES completion:NULL];
         
     }];
    
}