want to open new window on click of menuitem using navigateurl

Hi,

I need to open a new window on click of a menu item and its using navigateurl as mentioned below.

I tried this it opens a new new tab instead of a new window, I just want a new window and current page need not to be updated, what other things i can do.

  protected void navMenu_MenuItemDataBound(object sender, MenuEventArgs e)
    {

        //webhelp changes
        if (e.Item.NavigateUrl.Contains("PageURL=MenuWebHelp"))
        {
            string PopupWindowScript = @"javascript:window.open('/Medicare/Medicare/Help/Help.aspx?PageURL=', 'HelpDocs', 'top=50,left=50,width=800,height=800,location=no, status=no, menubar=no, scrollbars=no, resizable=yes,').focus();";
           e.Item.NavigateUrl = PopupWindowScript;
                       e.Item.Target = "_blank";
           
           
        }

        if (e.Item.NavigateUrl.Contains("#"))
        {
            e.Item.NavigateUrl = "";
        }
    }