docs: public void setAlias(String alias)
  	{
  		if (alias == null || alias.trim().equals(""))
  		{
  			m_alias = null;
  		}
  		else
  		{
  			m_alias = alias;
  		}
  
  		// propagate to SelectionCriteria,not to Criteria
  		for (int i = 0; i < m_criteria.size(); i++)
  		{
  			if (!(m_criteria.elementAt(i) instanceof Criteria))
  			{
  				((SelectionCriteria) m_criteria.elementAt(i)).setAlias(m_alias);
  			}
  		}
  	}