I have a table with 50 rows. I want to select particular rows with checkmark accessory but when i select some rows and scroll down the table then i see pre checked rows. I know that table cell are reused but i want to emit this problem what can i do about this?

 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
   // return [array count];
    return 50;
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";

  TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    if (cell == nil) {
        cell = [[[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

    }
    cell.textLabel.text=[NSString stringWithFormat:@"%i",[indexPath row]];
    return cell;
}

// Override to support row selection in the table view.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

    if (cell.accessoryType == UITableViewCellAccessoryNone) {
        cell.accessoryType = UITableViewCellAccessoryCheckmark;

    } else {
        cell.accessoryType = UITableViewCellAccessoryNone;
    }