Anyone know how to close a window in the admin, I made my own image editor so when you click on edit image in the image properties it loads up and works but I cannot get the opened window to close again,

below is the edited code to get the window to open, then I changed imageeditor.php for mine,

//"<img id='thumbnailImage' src='{$thumbnail}?r=" . rand(1,100000) . "' alt='{$childData->Name}' />"            )
            '<a id="ImageEditorActivator" href="javascript: void(0)">' . "<img id='thumbnailImage' src='{$thumbnail}?r=" . rand(1,100000) . "' alt='{$childData->Name}' /><p>"._t('AssetTableField.EDITIMAGE', 'Edit this image')."</p>" . '</a>' .
                  '<script type="text/javascript" src="cms/javascript/ImageEditor/Activator.js"></script><script type="text/javascript">var imageActivator = new ImageEditor.Activator.initialize();Event.observe("ImageEditorActivator","click",imageActivator.onOpen);</script>')