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:
  _____   ___    ____   _  __  ____ 
 / ___/  / _ )  /  _/  | |/_/ / __ \
/ /__   / _  | _/ /   _>  <  / /_/ /
\___/  /____/ /___/  /_/|_|  \____/