Injecting code into a child frame

<!-- http://stackoverflow.com/questions/18342200/how-do-i-call-eval-in-ie-from-c/ -->
<head>
<script>
function Test()
{
    var ie = new ActiveXObject("InternetExplorer.Application");
    ie.Visible = true;
    ie.Navigate("http://jsfiddle.net/");

    WhenLoaded(ie, function() {
        // injector code
        var __execScript = "window.__execScript = function(exp) { return eval(exp); }";

        // inject into main window
        ie.Document.parentWindow.eval(__execScript);
        ie.Document.parentWindow.__execScript("alert(document.URL)");

        // inject into a child frame - from the context of the main window
            ie.Document.parentWindow.__execScript('document.all.tags("iframe")[0].contentWindow.eval("' + __execScript + '")');
        ie.Document.parentWindow.document.all.tags("iframe")[0].contentWindow.__execScript("alert(document.URL)");
    });

}

function WhenLoaded(ie, loaded)
{
    if (ie.readyState === 4)
        loaded();
    else
        setTimeout(function() { WhenLoaded(ie, loaded); }, 250);
}
</script>
</head>

<body>
<button onclick="Test()">Test</button>
</body>