How to Discontinue Processing in Response to MsgBox?

Greetings All,

My question is,

• How do I stop further processing in response to a particular returned MsgBox value?
• I have placed a MsgBox script on the change event of a drop-down box.
• Depending on the return value, I don't want subsequent events for the drop-down box to fire (like the scripts on its exit event)
  
• I also want the entire form ready for the next interaction by the user (not locked-down)
• Is there is a way to get the processing to "break" and not fire subsequent  events that are already triggered and waiting their turn to execute?

Thanks,

Stephen