How do I take data from 3 different fields and display them in one field on results page

How do I take data from 3 different fields and display them in one field on results page

Hello,

I have a form in which there are 3 different fields related to Invoice numbers. What i want to do is have the data displayed under one row on the results page. 

Example

Form:
Invoice Number #1 [   0001   ]
Invoice Number #2 [   0002   ]
Invoice Number #3 [   0003   ]

Results Page:
Invoice Numbers [ 0001, 0002, 0003]

Can someone please provide an example of the script that i would use to do this?

Thank you in advanced.