window this

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>window this</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.6.4.min.js"></script>
<script type="text/javascript">
(function($)
{
        function init()
        {
                window.name = 'parent';

                window.meh = function()
                {
                        alert('meh:' + this.name);
                }

                $("#create").click(function()
                {
                        // Open an empty popup we're going to fill in js (so that demo requires only one file)
                        var W = window.open('', 'myWindow');
                        W.name = 'child';

                        // Using writeln, which is extacly like referencing a js file for my example
                        W.document.writeln('<html><head>'+
                        '<title>newWindow</title>'+
                        '</head><body>'+
                        '<script type="text/javascript">'+
                        //'alert(this.name);'+ // this is resolved to W (popup window), so alert outputs 'child'
                        //'window.opener.meh();'+ // guess what, 'child' or 'parent'? 'parent' of course !
                        'var MEH = window.opener.meh; MEH();'+ // and now ? yeah 'child'
                        '</scr'+'ipt>'+
                        '</body></html>');
                });

                var MEH = window.meh; MEH(); // 'parent'

                /*
                        Take a careful look at the 2 MEH() calls.
                        `this` resolution depends on where the js source that triggers the call stack is coming from.
                        Not we're the function currently executed is written (meh function declaration).
                */
        }

        $(init);
})(jQuery);
</script>
</head>
<body>
  <input type="button" id="create" value="Click Me" />
</body>
</html>