How to prevent users from submitting the same combination of selected fields on the form?

Hi there! I’m creating a form for a fundraiser we’re running called the “Ball Drop.” I need some help setting up the form correctly to avoid duplicate number selections.

Here’s how it works:

• Each participant picks one color sheet (either White or Green).
• Each color sheet contains a sequence of 20 numbers, and numbers range from 1 to 500.
• Once a person selects a color sheet and a number group, it must be marked as “signed out” and made unavailable to others.

My goals for this form:

1. Allow users to choose a color sheet (White or Green).
2. Let them select an available sequence of 20 numbers (e.g., 1–20, 21–40, etc.) without duplicating already selected groups.
3. Prevent anyone from selecting a number group that has already been signed out.
4. Ideally, display only available options to avoid confusion.

What’s the best way to build this in JotForm? Should I use conditional logic, dropdowns, or integrate with a spreadsheet to track assigned numbers?

Thank you for your help!

Hi Ashley,

Thanks for reaching out to Jotform Support. You can copy the combination selected by the user on a Short Text field using conditional logic and then enable the Unique Field feature of your form to prevent having multiple submissions with the same combination. Let me show you how to do it:

1. In Form Builder, click on Add Element on the upper left side of the page.

2. Drag and drop a Short Text widget from the left side of the page to your form.

3. Click on Settings on the orange navigation bar at the upper part of the page.
4. In the menu that opens on the left side of the page, click on Conditions.
5. Click on Update/Calculate Field on the list.

6. Copy the conditional logic settings below.
7. Click on Save on the lower part of the page.

8. In the left side of the page, click on Form Settings.
9. Click on Show More Options on the lower part of the page.

10. Scroll down the page, and in Unique Field, select your Short Text field.

If that’s not exactly what you’re looking for, can you explain a bit more so I can help you better?

Once we hear back from you, we'll be able to help you with this.