JavaScript program to take a year as input and tells whether it's a leap year or not

Following program shows you how take a year as input and tells whether it's a leap year or not.

var input = prompt("Enter a year:");
if (input % 4 == 0) {
    if (input % 100 == 0) {
        if (input % 400 == 0) {
            console.log(input + " its a leap year");
        } else {
            console.log(input + " its not a leap year")
        }
    } else {
        console.log(input + " its a leap year")
    }
} else {
    console.log(input + " its not a leap year")
}

Output:

Example1:

Enter a year:
1980
1980 its a leap year

Example2:

Enter a year:
2001
2001 its not a leap year