I've search everywhere in this forum and in opencart extension as well but didn't find this feature/extension.

I have a product options that need to show/visible only if user select another options:
some example:
I have a dress with size options: S, M, L, XL, and Custom. If user select 'Custom', another product options (input text) will show: "Waist", "Bust", "Hip"
Another example:
- I have a custom party banner with individual letter/character.
- If user check the options "Add additional flag", another product options will show: "Number of flag".
- If user select "1", another one "Character" options will show
- If user select "2", another two "Character" options will show
- If user select "3", another three "Character" options will show
Actually I think many people will need this feature but weirdly there is no extension for this feature.
I know I could do this with jQuery, but since the ID is dynamically created for each product, I will need to make a script for each product, which is very not comfortable at all. Say, everytime I upload a dress, I will need to add another jQuery scipt in my product.tpl.
Thankyou for your help
