Block show the default VtigerCRM Confirmation box to let them decide something.
You could configure the text, the User see.
This configuration result into this in Frontend:

Enter your comment. Wiki syntax is allowed:
   __ __  _      __     __   ____   ____
  / // / | | /| / / __ / /  /  _/  /  _/
 / _  /  | |/ |/ / / // /  _/ /   _/ /  
/_//_/   |__/|__/  \___/  /___/  /___/