Hi there,
Have a look on the Scotlands People site (
www.scotlandspeople.gov.uk)
The site is pay per view, but it is well worth it. You can see the image of the actual entry in the register. The marriage cert will show both sets of parents. From there you will be able look for birth certs on the site for both Robert and Janet, their parents' birth, marriage and death certs. There are census records from 1841 to 1901 on there too.
Good luck with the search

Cheers,
Clare
P.S it is not recommended that you post you personal email address on these sites as it can leave you open to malicious use of the email address (not by rootschatters, but Google picks up information within messages here, so non-rootschatters can get access). People who want to contact you can always reply to the post or send you a personal message via your login name on the site.