javascript question like alert code example

Example 1: js alert yes no

if (confirm('Are you sure you want to donate to Andrew Hyder?')) {
  // true (paypal.me/andrewdhyder)
} else {
  // false
}

Example 2: javascript prompt

var person = prompt("Please enter your name", "Harry Potter");

if (person != null) {
  document.getElementById("demo").innerHTML =
  "Hello " + person + "! How are you today?";
}