I'd like this stochastic to cross down from 80 (overbought) and display a signal, but it's not plotting at all. What am I doing wrong?

Plot Data = (FullK[1] > FullD[1]) and (FullK < FullD) and (highest (FullK[1],3) crosses below 80);

Are there more sound that just bell? What other sounds may I change to? How do I have it display an alert message too?

Alert(highest (FullK[1],3) crosses below 80, "", Alert.BAR, Sound.Bell);

Is there a way to combine the above two codes into one - crosses below 80 and give alert?
Please advise. Thank you.

Kim