You can add a hidden field for each of the 3 messages.
Set the default or initial value of each to 'true'
When you trigger the code that displays the message, check to see if the value in the hidden field is 'true'.
If it is, show the message, and set the field to 'false'
If when checked, the associated field is 'false', take no action on the display.
Up to you if you want the messages only once on the life of the form, or once each time the form is opened.
If you want them only once ever, you will need to save the data along with your other form data, and adjust the initialize logic.
Hope this helps.
Mark