I have a form that contains a collection. in the collection there are two fields. The first field is a drop down field that contains some values. The second field is a check box field that has three options (A, B and C).

Based on the value selected from the drop down menu, the checkbox values should be updated automatically.

For example:

If user choose "George" from drop down menu, then the check box field should show A and C checked

If user choose "Bob" from drop down menu, then the check box should show B checked

etc. 

Both the Drop Down and Checkbox fields do not have function option to create a formula for setting appropriate values. How can I achieve the above concept? Thanks.