set_message
Description:
Sets the prompt message for the user.
A prompt implementation should always display this message.
Parameters:
| this | 
           the prompt  | 
      
| message | 
           the prompt message  | 
      
Sets the prompt message for the user.
A prompt implementation should always display this message.
| this | 
           the prompt  | 
      
| message | 
           the prompt message  |