Forms. How update questions to avoid overbooking

[Salvatore Valenza]

I'm trying to create a form to order some products trough some ItemList (1, 2, 3, 4, 5) questions to express the quantity.

What I want is to avoid overbooking.  I managed the products availability in the connected spreadsheet but i'm not able to reduce the answere when quantity available is less than 5 and to avoid more order when the availability is 0.

I just need some suggestion. Than I can adapte the code for my cases.

Thanks in advance.

[Tanaike]

Unfortunately, from your question, I cannot understand your actual situation. So, how about the following patterns?

Pattern 1

When the quantity available is changed by submitting the Google Form, how about modifying the questions of Google Form when the Google Form is submitted?

Pattern 2

When the quantity available is NOT changed by submitting the Google Form and the Spreadsheet is changed by some users and the webhook by Sheets API, how about modifying the questions of Google Form when the Spreadsheet is changed?

If I misunderstood your question and those were not useful, I apologize.