<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="style.css">
<script src="script.js"></script>
</head>
<body>
<form id='form1' name='form1' action='' method='post' target='bigIframe'>
<input id='inData' name='inData'>
<input id='btn1' type='submit'>
<iframe id='bigIframe' name='bigIframe' src='child.html' width='400' height='300'></iframe>
</form>
<script>
var form1 = document.getElementById('form1');
form1.addEventListener('submit', function(e) {
e.preventDefault();
var bigI = document.getElementById('bigIframe');
var data = document.getElementById('inData').value;
var iUser = bigI.contentWindow.document.getElementById('user_name');
iUser.value = data;
}, false);
</script>
</body>
</html>
// Code goes here
/* Styles go here */
<!DOCTYPE html>
<html>
<head>
<link rel="stylesheet" href="style.css">
<script src="script.js"></script>
</head>
<body>
<input id='user_name' name='user_name'>
</body>
</html>