public function enable($name = null)
	{
		// Check if it exists. if not, bail out
		if ( ! $this->field($name))
		{
			throw new \RuntimeException('Field "'.$name.'" does not exist in this Fieldset.');
		}

		if (isset($this->disabled[$name]))
		{
			unset($this->disabled[$name]);
		}

		return $this;
	}