Above characters are (deliberately) badly written.
First is obviously an upper case letter, second is a numeral,
third is a lower case letter near start of alphabet,
Fourth is a reasonably clear upper case letter from near middle of
alphabet and final one is a numeral.   Purple blobs have no
significance apart from helping to confuse.   Please check you're
using the correct case when typing your response.   Hopefully this
simple test will be too much bother for the spammers who messed about
with our last guest book.   I have also tried to overcome
the problem where the amount of input text for your comments
was limited.   There is of course still a limit but it
shouldn't worry too many.
N.B. One small point that has already confused several members.
If you look at the Guestbook immediately after posting a comment
but don't see what you've just posted,   try pressing
the 'Refresh' button on your internet browser. Sorry, but reading the entries
is a facility reserved for members only.