Yes, you can add fields from related tables. To add just one related record, choose Field… from the Insert menu and pick a related table (Expenses) from the pop-up menu. Ensure that you have checked the checkbox "Allow creation of records in this table via this relationship" for the Expenses when you edit the Relationship.
If you have multiple expenses for each research project, add a 'Portal' of the expenses table occurrence to your research layout. Portals have multiple columns and rows that can be used to add, display, and delete related records from another table. This way, you can add any number of expenses against each research project.
For details on how to create portals, please take a look at the topic: "Creating portals to hold related records" in the FMP Help menu item.
TQ Jade for your helpful explanation, I got it.
Jade or any FMP expert,
I have one more question. I have multiples expences for each research/project. I already design 1 layout that
combine 2 tables (research & expenses).
I want to make my system friendly. Let say in same research, I want to make another expenses. So, user no
need to key-in the same data for research. What the need to do is only add the new expenses data.
Could plese help me how to do that.
FYI, my tables are:
research (research_account_no, researcher_name etc)
expenses (po_no, invoice_no etc.)
* relational field : research_account_no
You can either create a script that creates a record in the Expense table:
Set Variable [ $acctnum; research::research_account_no ]
Go to Layout [ "Expense" ]
New Record 
Set Field [ expense::research_account_no; $acctnum ]
Go to Layout [ Orig ]
or if you dont mind creating a new record in the portal itself you can just turn on "Allow Creation of Records" in your relationship on the expense table side.
I have tried to create script and the result as below.
Set Variable [ $acctnum; Value:research::research_account_no ]
Go to Layout [ "Input Screen" (research) ]
New Record/request 
Set Field [ expense::research_account_no ]
Go to Layout [ Original layout ]
I realized that, the is no $acctnum in the line Set Field (line 5) as your given code,
I don't know how to add this. When, i run this script it still add
data in table research when I want to add another expenses.
Please advice me
In the set field step, where the calculated result goes, just manually type: $acctnum
Also the reason that you are still creating a new record in accounts is because you are not going to a layout based off EXPENSE. Please take a closer look at the script in my earlier post.
TQ so much, I got what i mean.