<!DOCTYPE html>
<html>
<head><title>Simple Interest</title></head>
<body>
<h2>Simple Interest Calculator</h2>
Principal: <input id="p"><br><br>
Rate: <input id="r"><br><br>
Years: <input id="t"><br><br>
<button onclick="calc()">OK</button>
<script>
function calc(){
let p = document.getElementById("p").value;
let r = document.getElementById("r").value;
let t = document.getElementById("t").value;
let si = (p * r * t) / 100;
alert("Simple Interest = " + si);
}
</script>
</body>
</html>