Display a dialogue box message.
Syntax 
      MsgBox(prompt [, buttons][, title]
         [, helpfile, context])
Key
   prompt    The dialogue box text.
 
   buttons   The sum of the constants for button, icon, default button and modality
   title     Title bar text
   helpfile  A helpfile to link to the help button
   context   Helpfile context number
Constants
  Buttons: vbOKOnly (0), vbOKCancel(1), vbAbortRetryIgnore (2), vbYesNoCancel(3)
           vbYesNo (4), vbRetryCancel (5)
  Icon: vbCritical (16),vbQuestion (32),vbExclamation (48), vbInformation (64) 
  Default button: vbDefaultButton1 (0),vbDefaultButton2 (256),vbDefaultButton3 (512),vbDefaultButton4(768)
  Modality: vbApplicationModal, vbSystemModal
The MsgBox function will return one of the following:
 1 =  OK was clicked (vbOK) 
 2 =  Cancel was clicked (vbCancel ) 
 3 =   Abort was clicked (vbAbort) 
 4 =  Retry was clicked (vbRetry) 
 5 =  Ignore was clicked (vbIgnore) 
 6 =  Yes was clicked (vbYes) 
7 =  No was clicked (vbNo) 
Examples
'Display a message:
result=Msgbox("Are you sure?",vbYesNo+vbInformation, "")
WScript.Echo result
“Everyone has an invisible sign hanging from their neck saying, Make me feel important. Never forget this message when working with people” ~ Mary Kay Ash
Related:
InputBox - Prompt for user input.
Equivalent PowerShell: MessageBox - Display a message box to the user.