Write a JavaScript program to create a function called sum() to add two numbers.
<html>
<head>
<title>Function to calculate sum of two numbers</title>
<script>
function sum(val1, val2)
{
var result = val1 + val2;
document.write(result + "<br/>");
}
</script>
</head>
<body>
<script>
sum(23, 19);
sum(32, 56);
sum(12, 52);
</script>
</body>
</html>
