script.js

function compute() {
  var principal = document.getElementById("principal").value;

  if (principal == "" || principal <= 0) {
    alert("Enter a positive Number");
    document.getElementById("principal").focus();
    return;
  }

  var rate = document.getElementById("rate").value;

  var years = document.getElementById("years").value;

  var interest = (principal * years * rate) / 100;

  var year = new Date().getFullYear() + parseInt(years);

  document.getElementById("result").innerHTML =
    "<br/> <br/> If you deposit " +
    "<mark> " +
    principal +
    "</mark>" +
    ",<br> at an interest rate of " +
    "<mark>" +
    rate +
    " % </mark> " +
    "<br> You will receive an amount of " +
    "<mark>" +
    interest +
    "</mark>" +
    ",<br> in the year " +
    "<mark>" +
    year +
    "</mark>" +
    "<br>";
}

function updateRate() {
  var rateval = document.getElementById("rate").value;
  document.getElementById("rate_val").innerText = rateval + "%";
}