Google Apps Script can be intimidating at first. On of the early functions I needed to use was alerts. This is a simple program to show how to use an alert in Apps Script.

Using Alerts in Google Apps Script

// Kurt Kaiser
// kurtkaiser.us
// All rights reserved, 2019

var ui = SpreadsheetApp.getUi();

function onOpen() {
  ui.createMenu('Alert System')
  .addItem('Alert Me!', 'showAlert')
  .addToUi();
}

function showAlert(){
   ui.alert('I am alerting you!');
}