Demath, зачем писать то что есть?
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery UI Dialog - Default functionality</title>
<link rel="stylesheet" href="http://code.jquery.com/ui/1.11.1/themes/smoothness/jquery-ui.css">
<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<script src="http://code.jquery.com/ui/1.11.1/jquery-ui.js"></script>
<link rel="stylesheet" href="http://jqueryui.com/resources/demos/style.css">
<script>
$(function() {
$( "#dialog" ).dialog();
});
</script>
</head>
<body>
<div id="dialog" title="Basic dialog">
<p>This is the default dialog which is useful for displaying information. The dialog window can be moved, resized and closed with the 'x' icon.</p>
</div>
</body>
</html>
а вот ссылки
http://jqueryui.com/dialog/
http://jqueryui.com/dialog/#animated
http://jqueryui.com/dialog/#modal-confirmation
http://jqueryui.com/dialog/#modal-form
http://jqueryui.com/dialog/#modal-message