volume of the ellipsoid by javascript---

i am posting here the html and java script code can you please rewrite the code again and tell me what is wrong with my code?

----------html-------

volume of an ellipsoid

a

b

c

© Author(s): noone

--------javascript------

function volume() {

//precondition: n1, n2, n3 belongs to whole numbers

//postcondition: volume is calculated and outputted

var n1 = parseFloat(document.getElementById("number1").value);

var n2 = parseFloat(document.getElementById("number2").value);

var n3 = parseFloat(document.getElementById("number2").value);

var x = ((4/3)*(3.141592654));

var vol = (x*n1*n2*n3);

document.getElementById("output").innerHTML = "volume:"+vol;

}

function changeColorover() {

document.getElementById("butn").style.color = "red";

}

function changeColorout() {

document.getElementById("butn").style.color = "DarkSlateGrey";

}