How can I prevent users from selecting an option from a dropdown field that was already chosen by someone else?

I have a drop down menu field and when an item in the field list is full, I would like to make it inactive but keep the other options in the field active.

I'm assuming what you meant to ask was how to prevent users from picking an Advising Session schedule that was already picked by someone else. If so, that can't be done with a regular Dropdown field.

Perhaps one of these two widgets might fit your needs:

1. Appointment Slots widget: http://widgets.jotform.com/widget/appointment_slots

2. Date Reservation widget: http://widgets.jotform.com/widget/date_reservation

Related guide: How-to-Add-a-Widget-to-your-Form

Give it a spin and don't hesitate to let us know if you need more help.

No that's not what I need:

I have a Drop Down field on my form and I only want 20 entries for each of the Items listed in the drop down menu field. For each Item that reaches 20 entries, I want it to be removed from the list.

How do I do this?

From how you further described it, if an option on your Advising Session Dropdown menu reaches 20 entries, it should be removed. Sorry but that can't be done with a regular Dropdown Field (nor any regular field for that matter).

Only widgets are capable of keeping track of user selection across submissions. These widgets were designed solely for that purpose (among with many others).

e.g. Some use case scenarios:

You want to keep track of your inventory, use the Inventory widget.

You want to set schedules on specific dates, use the Date Reservation widget.

You want to allow users to pick an appointment slot, use the Appointment Slots widget.

I recommend you browse around our Widgets Gallery if you think the widgets we recommended won't fit your requirements.

I didn't find a widget but it's too bad Jotform doesn't have this :(

Can you take a look at this demo form https://form.jotform.com/70305702530948 and see if that will work?

I used the Appointment Slots widget for your Advising Session field. I submitted and tested it once, and picked Fri March 10, 2:00PM. You would notice that the counter for the available slots for that session is now down to 19.

The same idea will take effect for each submission until the counter reaches zero. Once there are no more slots left, no one can select that slot anymore.

Isn't that how you wanted your form to behave? If that fits the bill, you may clone my form (here's how) or just add the Appointment Slots widget to yours.

I can not have the field provide multiple selections. How do I that. Other wise this will work perfectly.

I updated my demo form. Instead of using the Appointment Slots widget, I used the Ticket Purchases widget.

This has an added option of min/max selection to achieve what you want (e.g. disallow multiple selection).

THIS TOTALLY WORKED...YOU TOTALLY ROCK!!!

Thank you!!!