Alerts in MT4 indicators

I’d like to build a couple of indicators that will send me an alert based on other indicator criteria. Do indicators send alerts, or is it EA’s that send email alerts?

I already know to grab indicator data, so I think I can accomplish what I want, although I haven’t spent a lot of time with the MT4 language yet. But, maybe it’s already been done? Like Stochastics K crossing D, or MACD pulling away form the signal line? Of course I will ad some other critera, but just wondering if I can do it with a custom indicator (or is it an EA) and if it’s already been done and someone has something laying around that may only need a slight tweak from me.

Indicator send alerts to screen, email or phone. They have to have to code inside to do it. There is free indicator thread here that has indicator with alerts. I found free indicator with google.