Display A Random Messagebox Out Of Nine Choices?

i'm trying to display a random messagebox that displays a message associated with a character. the character image displays and the user clicks a button to guess the character if it is correct, one of three messages should randomly appear that is associated with that character (there are 4 characters, so there are 12 possible messages total. 3 for each character) but as it stands now, the picture box on the form displays the character name so the user doesn't have to guess which button to push. i need to remove the name from beneath the picture so only the buttons have the name and the user is forced to guess and i don't have the messages randomly popping up. only a messabebox that says correct i added a message box in the code but i can't figure out how to randomly get the messages associated with the characters to appear?

Imports System.IO
Public Class Form1
Dim currImageIndex As Integer = 0
Dim characterNames As String() = New String() {"Donny", "Jesus", "Lebowski", "Walter"}

[code].....