<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>bmi</title>
</head>
<body>
<script>
function bmi() {
var height = document.getElementById("height").value;
var weight = document.getElementById("weight").value;
var bmicompute = weight * 10000 / (height * height);
document.getElementById("bmivalue").value = bmicompute.toString().substr(0,4);
}
</script>
height<br>
<input type="text" id="height">cm<br>
weight<br>
<input type="text" id="weight">kg<br>
bmi<br>
<input type="text" id="bmivalue"><br>
<button onclick="bmi()">compute</button>
</body>
</html>