How to reduce the distance between sections in UITableview

Use all these methods to reduce the height between sections in tableview

-(CGFloat)tableView:(UITableView*)tableView heightForHeaderInSection:(NSInteger)section
{
      return 3.0;
}

-(CGFloat)tableView:(UITableView*)tableView heightForFooterInSection:(NSInteger)section
{
    return 3.0;
}

-(UIView*)tableView:(UITableView*)tableView viewForHeaderInSection:(NSInteger)section
{
    return [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 0)] autorelease];
}

-(UIView*)tableView:(UITableView*)tableView viewForFooterInSection:(NSInteger)section
{
    return [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 0)] autorelease];
}