Function onGUI

A “function onGUI” is not working for me. So, I debug by removing everything and keep only:

function Update (){
 Debug.Log("Update");
}
function onGUI () {
 Debug.Log("onGUI");
}

… and the console shows only: Update, not OnGUI! Yet the Reference Manual states, and I quote: “The OnGUI() function gets called every frame as long as the containing script is enabled - just like the Update() function.

Since I get the “Update” on the console, then my script is enabled. What could be wrong? I don’t understand because I have, in the same scene, another script calling onGUI and that one works as it should.

Because onGUI is not OnGUI