code: public static String getErrorSeverityClass(String clientId) {
  		String[] levels = { "bf-no-message has-success", "bf-info", "bf-warning has-warning", "bf-error has-error", "bf-fatal has-error" };
  		int level = 0;
  		Iterator<FacesMessage> messages = FacesContext.getCurrentInstance().getMessages(clientId);
  		if (null != messages) {
  			if (!messages.hasNext()) {
  				return "";
  			}
  			while (messages.hasNext()) {
  				FacesMessage message = messages.next();
  				if (message.getSeverity().equals(FacesMessage.SEVERITY_INFO))
  					if (level < 1)
  						level = 1;
  				if (message.getSeverity().equals(FacesMessage.SEVERITY_WARN))
  					if (level < 2)
  						level = 2;
  				if (message.getSeverity().equals(FacesMessage.SEVERITY_ERROR))
  					if (level < 3)
  						level = 3;
  				if (message.getSeverity().equals(FacesMessage.SEVERITY_FATAL))
  					if (level < 4)
  						level = 4;
  			}
  			return levels[level];
  		}
  		return "";
  	}
docs: Returns style matching the severity error.
  
  @param clientId
  @return