You can accomplish some surprisingly sophisticated tasks
with this small number of programming concepts. You collect sets of ECMA
Script statements designed to perform a specific task into functions.
Think of a function as a recipe card that gives a list of ingredients
and instructions which, when followed, create a specific dish. A
function starts with the keyword function
followed by the function name. The
name should be indicative of the task that it does, and it follows the
same rules that variable names do. Following the function name, in
parentheses, are the parameters of the function. A parameter is extra
information that the function needs when it does its task. Consider this
imaginary recipe: