Accessing data in multiselect fields, those involving stringlists

Accessing data in multiselect fields, those involving stringlists

I'm having trouble accessing data from multiselect fields.  In the form I am using, I have a field hidden (Graduating Class) when the form loads.  If the user chooses "alumnus" from a list of check boxes for affiliation with my school, I'd like to then show the hidden field "Graduating Class".  However, when I try to script something like  when input.Affiliation == "Alumnus", I get an error message saying the left side contains a stringlist, while the right side contains a string...

Any ideas?

Thanks!