function calculate_change () {

var input = prompt('Enter the amount');

var message = "You want to change " + input + "$, right?<br>";

//coins used in US...
var quarter = 0.25;
var dime = 0.10;
var nickel = 0.05;
var cent = 0.01;

//calculating the change
var quarters = input/quarter;
var dimes = ((input%quarter).toFixed(2))/dime;
var nickels = ((((input%quarter).toFixed(2))%dime).toFixed(2))/nickel;
var cents = (((((input%quarter).toFixed(2)%dime).toFixed(2))%nickel).toFixed(2))/cent;

message += "Quarters: " + Math.floor(quarters) + "<br>";
message += "Dimes: " + Math.floor(dimes) + "<br>";
message += "Nickels: " + Math.floor(nickels) + "<br>";
message += "Cents: " + Math.floor(cents) + "<br>";

document.write(message);
}