How do I make a field unfillable if someone choses a particular option

In the registration form for our conference, attendees can chose to either come for the whole conference, or just a day. I would like the two subsequent fields to be fillable depending on the choice the attendee makes.

Eg. If they are wanting to attend the full conference, they will NOT be able to select any payment options for the daily rates. Alternatively, if they are only attending one day, they cannot chose a full registration payment option.

How do i set the rules for the fields to do this?

Hi,

This is possible using conditional logic:

http://www.jotform.com/help/57-Smart-Forms-Using-Conditional-Logic

Click on the conditions tab in the form builder then setup up two hide/show conditions as follows:

Here is my test form to show you it working:

http://form.jotformpro.com/form/50055307018950?

Let us know if you have any further questions and we will be happy to help.

Thanks so much, David! Your answer was clear and easy to follow - and worked brilliantly!

You are very welcome!  Glad to hear it.  Let us know if there is anything else we can assist you with and we will be happy to do so.