public function html($client=null)
	{
		$this->setRendered(true);
		$id = self::idPrefix.$this->id;
		$return  = '<div class="'.self::elementClass.'">';
		$result = "<fieldset ".
			"id=\"{$id}_container\" ".
			">";
		if(isset($this->title))
		{
			$result .= "<legend>{$this->title}</legend>";
		}
		// children level 2 or deeper will be at the end of list so
		// when their parent get rendered they will be rendered too
		foreach($this->children as $child)
		{
			$child->setRendered(false);
		}
		foreach($this->children as $child)
		{
			if(!$child->isRendered())
			{
				$result .= $child->html($client);
			}
		}
		$result .= '</fieldset>';
		return $result;
	}