Untitled

<!DOCTYPE html>
<html>
<head>
	<title>Title</title>
</head>
<body>
	<h1>Fiuid Form</h1>
	<input type="text" id="num1"><br>
	<input type="text" id="num2"><br>
	<input type="text"id="sum"><br>
	<input type="text" id="mul" ><br>
	<input type="text" id="total"><br>
	<input type="submit" value="Save" onclick="my()">

	<script type="text/javascript">

		function my(){
			var num1 =Number(document.getElementById('num1').value);
			var num2 =Number(document.getElementById('num2').value);
			var mul =Number(document.getElementById('mul').value);
			var sum = num1+ num2;
			var sumresult = document.getElementById('sum').value=sum;
			var total = sumresult* mul;
			document.getElementById('total').value=total;
		}
	</script>
</body>
</html>