function greetingHandler() {
	// Gather the page elements we need to interact with
	let nameField = document.getElementById('name');
	let resultPar = document.getElementById('result');
	
	// Get the name the user entered.
	let name = nameField.value;
	
	// Construct a greeting
	let greeting = 'Hello, ' + name + '. Welcome to JavaScript!';
	
	// Present the result
	resultPar.textContent = greeting;
}

function setup() {
    let greetingButton = document.getElementById('greeting');
    greetingButton.addEventListener('click',greetingHandler,false);
}

window.addEventListener('load',setup,false);