SPAM from ChronoForms

Hi
About week ago I started getting these letters (see in attach).
I looking what it could be but can't find out.
Now i just changed URL of form.
how you could see all fields filled by URLs and texts but it's not possible. In each field, I clearly have the format of input data.

Hi levazzz,

It's possible if the spammer has JavaScript turned off and most do. User serverside validation to block these. Please see this FAQ

Bob

yesterday I set anti-spam but today again received the same letter.
Will try all yours methods.
Thanks for replied.