function imagemanager(field_name, url, type, win) {
    var ajaxfilemanagerurl = "js/tiny_mce/fileManager.aspx";
    switch (type) {
        case "image":
            break;
        default:
            return false;
    }

    tinyMCE.activeEditor.windowManager.open({
        file: ajaxfilemanagerurl,
        title: 'Image Browser',
        width: 520,  // Your dimensions may differ - toy around with them!
        height: 400,
        resizable: "yes",
        inline: "yes",  // This parameter only has an effect if you use the inlinepopups plugin!
        close_previous: "no"
    }, {
        window: win,
        input: field_name
    });

    return false;
}