This is my first Infopath project.  It's pretty simple, but I am
totally stumped on one thing I want to do.  I've got everything else
working except this part.

I am entering class attendance.  I input the class code, the date and
the teacher(s), no problem.  The student information is a repeating
section.  I have a drop-down, populated by a secondary source, that
gives the student ID numbers.

When the user selects an ID number, how do I make it look up the name
of the student and display it?

Thanks in advance.