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