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Error: cannot call methods on dialog prior to initialization; attempted to call method 'close'.
jquery-latest.js (line 507)

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title>jQuery UI Dialog</title>
        <script src="http://code.jquery.com/jquery-latest.js" type="text/javascript"></script>
        <link type="text/css" href="http://code.jquery.com/ui/1.9.0/themes/base/jquery-ui.css" rel="stylesheet" />
        <script src="http://code.jquery.com/ui/1.9.0/jquery-ui.js" type="text/javascript"></script>
        <script>
            $(function() {
                $("#open").click(function(){$("#dialog").dialog('open');return false;});
                $( "#dialog" ).dialog({
                    modal: true,
                    autoOpen    : false,
                    buttons: {
                        Ok: function() {
                            $( this ).dialog( "close" );
                        }
                    }
                });
            });
        </script>
    </head>
    <body>
        <button id="open">Click</button>
        <div id="dialog" title="What ever"></div>
    </body>
</html>