parent.history.back();
[OR]
document.referrer;
A.html
<html>
<body>
From Page A
<a href="C.html">Next</a>
</body>
</html>
B.html
<html>
<body>
From Page B
<a href="C.html">Next</a>
</body>
</html>
C.html
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("#back").click(function() {
parent.history.back();
});
});
/* $(document).ready(function(){
$("#back").click(function() {
var previousPage = document.referrer;
window.location.href = previousPage;
});
}); */
</script>
</head>
<body>
From Page C ...
<button id="back">Back</button>
</body>
</html>
