Need help with Query to determine timestamp difference between two fields

[webguync]

I have two tables with two fields, both timestamps. I need to set up a Query to subtract the difference in minutes between the two fields (login_timestamp and submit_timestamp). login_timestamp is in a table called 'Candidates' and submit_timestamp is in a table called 'Responses'. I believe I would need to use.

SELECT TIMESTAMPDIFF(MINUTE,'2010-05-17 12:26:13','2010-05-17 11:32:45');

 

but a little unsure about how to from two different tables.

 

Thanks in advance!