Chrome Extension: Open New Popup Window

Could someone shed some light on where this code is incorrect please

<script>
    chrome.browserAction.onClicked.addListener(function(window) {
        chrome.windows.onCreated.addListener(function(enumerated string ["popup"]) {
            chrome.windows.create({'url': chrome.extension.getURL('redirect.html')}, function(window) {
            });
        });
    });
</script>

I'm trying to achieve that when the extension is clicked on a new popup window will load.