Disable some fields for limited sections

I have 5 choices in a dropbox.  (e.g. 5 classes)

However, from time to time, some of them are full. But, i still want people to see them in the dropbox list. however, I will need to make the full classes non-selectable.  

Is it doable? 

Hi Stormingrobots,

Thank you for contacting Support.

This is doable, you may be able to use the inventory widget or the quantity gift widget to add a time and limit the quantity.

You can then use the form calculation and conditions to add calculate and add values to the widget.

I hope this helps.

Let us know if you need further assistance.

Sorry,  I should have been more specific.

One of them is full, but it is better to leave the description there so that people won't think we are missing an entry. 

I know that is doable as i did it from scratch on my site in the past.  But this does not seem to work in jotform.

Hi Stormingrobots,

Thank you for clarifying the issue.

May we confirm if you want the options quantities to be limited every time the class is full?

Unfortunately, we don't have a dynamic dropdown that would remove the option or close the option once it is full. 

To limit available items, it is achievable by using the inventory widget or the quantity gift widget.

I hope this helps.

Let us know if you need further assistance.