In the alertMe function the argument employed is "message" and is contained within the parentheses. The argument itself is passed to a stock standard alert() method.
To generate an argument to represent the message we can do this on the body onload event.
<body onload="alertMe('my name is Eddie')">
What this does is then pass 'my name is eddie' to the argument message and when the alert is triggered then my name is eddie is displayed in the alert dialogue. An argument is a system where you can pass information from an event to the function itself, which is particularly useful when working with programming languages.