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:
   ___   ____  __  __   ____   _  __
  / _ \ /_  / / / / /  / __/  | |/_/
 / , _/  / /_/ /_/ /  / _/   _>  <  
/_/|_|  /___/\____/  /_/    /_/|_|