Simple popup window by using html5 and javascript.
html:-
<dialog id="window">
<h3>Sample Dialog!</h3>
<p>Lorem ipsum dolor sit amet</p>
<button id="exit">Close Dialog</button>
</dialog>
<button id="show">Show Dialog</button>
JavaScript:-
(function() {
var dialog = document.getElementById('window');
document.getElementById('show').onclick = function() {
dialog.show();
};
document.getElementById('exit').onclick = function() {
dialog.close();
};
})();