public static bool IsClass(IntPtr hwnd, String className)
        {
            StringBuilder sb = new StringBuilder(256);

            WinUserApi.GetClassName(hwnd, sb, sb.Capacity);
            return(sb.ToString() == className);
        }
        public static String GetClassName(IntPtr handle)
        {
            StringBuilder className = new StringBuilder(256);

            WinUserApi.GetClassName(handle, className, className.Capacity);
            return(className.ToString());
        }