Write a JavaScript program to calculate multiplication and division of two numbers (input from user)

function multiplyBy()
{
        num1 = document.getElementById("firstNumber").value;
        num2 = document.getElementById("secondNumber").value;
        document.getElementById("result").innerHTML = num1 * num2;
}

function divideBy() 
{ 
        num1 = document.getElementById("firstNumber").value;
        num2 = document.getElementById("secondNumber").value;
document.getElementById("result").innerHTML = num1 / num2;
}