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