I've tried and cannot get Magic update to work with dropdowns fields, I've set a value of "na" in the table to test and added this code
.dbEditUpdateFlds "fi=1,fi=10,fi=11|,fi=2|ty=selectbox|val=MCCID|tex =MCCID|oper=EQ|comp=na,fi=3"
and regarless of what selection I use it will always give me the magic validate error. Adding the same code on a non dropdown field works fine.

I'm getting real frustated with dropdown fields and not being able to validate the user choice. It seems to me that using selectbox+b and then validating that the user made a choice(ie field is mandatory and blank is not acceptable) would be a very basic edit required on update and add functions.

Why is that not supported, a dropdown field is just another text field?