function myDogAge() {

var myAge = prompt("Enter your age")

//The first two years of a dog's life count as 10.5 dog years each.
var firstYears = 2 * 10.5;

//Each year following equates to 4 dog years.
var laterYears = (myAge - 2) * 4;

var myAgeInDogYears = firstYears + laterYears;

alert('My age in dog years is ' + myAgeInDogYears + '.'); }