Go to http://www.w3schools.com. Click “Try it yourself.”
Add your alert message to the HTML code.
Add tags to make the alert message bigger and bolder and to change the color to red.
In your document, create a new HTML file in the script editor. Name it “Opening Message HTML.”
Add your message after the first <body> tag.

*NOTICE -- THERE IS A KNOWN ISSUE WITH THIS LESSON: The onOpen popup message, when you first open the Google Doc, is currently not opening. When you manually run the script, if the popup message appears, then the code is correct.*