Validation Rules (Checkbox)

Dear All,

I have set up a custom field (checkbox) with 6 different values listed with (i) fee field enabled, and (ii) 6 corresponding fees. I am trying to limit the maximum number of selectable items to 2. Accordingly, I have set the validation rule as validate[required,maxSize[2]].

However, each time I check two items on the checkbox on my form, I get an error in a red box stating *Maximum2characters allowed.

In the circumstances, I would be grateful if I could explained how to fix the situation so I do not get an error message once two items are selected and also, if possible, I would like to know how to amend the error message when more than 2 items are selected.

Thank you in advance for your help!

Does setting max3 produce the validation rule effect you want - i.e. can select 1 or 2 check boxes but not 3? The message will probably still not make sense though?

If so its because it effectively is recording 1,2 as the response which is 3 characters. I'm sure someoen will be along to comment if the message can be customised?

It still gives an error message (now *Maximum3characters allowed).