Write a JavaScript program for retrieving characters from given string.
<html>
<head>
<title>Retrieving a character from String</title>
</head>
<body>
<script>
var txt = "JavaScript";
for(i = 0; i < txt.length; i++) {
document.write("charAt(" + i + ") : " + txt.charAt(i) + "<br>");
}
</script>
</body>
</html>
