Wondering how to reference a property from a field in the same table

Thanks for the quick response!

Sorry for the confusion, I'm learning the semantics still. My table is 'Tractors', and a field of the table is 'Available' and 'Tours'. This 'Tours' field is a relationship to another table called 'Tours' which has a Start Date/Time and End Date/Time.

So I would like to get those Start and End values for a formula in my 'Available' field. So some pseudocode:

'[Tours].StartDateAndTime ..... [Tours].EndDateAndTime'

Thanks again,
John

Update of the current situation:

So I decided to add an 'Available' field in my 'Tours' table that is populated based on Start and End time, which was successful. Thanks for the code snippet. (Although it would still be nice to know how to reference a field from another table)

However, I still want to populate the 'Available' field in my 'Tractors' table. Both of these tables have a 'Unit #' field, which would probably be the best way to retrieve if it is available or not.

The objective would be to get the Unit # from this 'Tractors' table, find the corresponding Unit # from the 'Tours' table, and populate the 'Available' field in 'Tractors' table to the same availability state in the 'Tours' tab.

Would this be the best route to take?
So:
1. Get Unit # from 'Tractors' table
2. Find Unit # in 'Tours' table
3. Get 'Available' from 'Tours' table
4. Set 'Available' in 'Tractors'

Thanks for any help.
John

Another update:

Starting to realize I can probably create a relationship based on these values. Can anyone lead me in the right direction. Sorry to constantly change my ideas, I was thrown into this head-first and have never used QuickBase

Thanks,
John