1<html> 2<head> 3<title>PostMessage Test</title> 4<script> 5var messagesReceived = 0; 6window.addEventListener("message", messageReceived, false); 7function messageReceived(event) { 8 messagesReceived++; 9 document.body.appendChild(document.createTextNode('Message ' + messagesReceived + '.')); 10} 11</script> 12</head> 13<body> 14Test page. 15</body> 16</html> 17