[AccessD] SQL Server BE - Access FE

Works good....
I can't seem to figure out how the security on the SQL Database can be
used.
When I first go into the FE, the forms work... when I need to look at
any of the data, I get an error message about the login failed for the
user.  I click the OK button and get another screen with Server visible
and the Use Trusted Connection checked.  When I uncheck the box, the
Login ID and Password are available to enter the correct information.
I've looked into the help and couldn't find what I needed. I have one
user in SQL Server with the correct security (Read-Only).

How do I connect without going through that sequence? 

TIA
Jim