Populating field in one table from another form

Populating field in one table from another form

I've looked around the forums a bit and have not found this subject expressly addressed.

I have a Client form with a multiple line field for jobs associated with this client.

I have a Jobs form that details the specifics of various jobs (all unique and assigned to a specific client). When I create a Job record, I want it to populate the jobs field in the Client record with the job name without having to go back to the Client record and manually populating the job list field.

I thought that upon success of adding a Job record, that I could run a script. Here is what I did, but it did not work:

job = clients [Last_Name == input.Client];
job.Jobs_List = "jobby";


Any ideas?