Question: Read Only fields in Chronoforms 7

I created a form in Chronoforms 7. I added a PHP action that checks in the database whether the logged-in user has already filled in this form and gives the var:reedsingevuld the value 1 if this is the case.

If the value of the fieldis 1, then I want to make the form Read only so that people cannot fill out the form a 2nd time. I can't manage to make the fields read only once the value of the field is 1. How can I solve this?

Thanks :-)

One way to do this, is to create 2 different forms. One can be filled and submitted, the other is read-only.

So when the user opens the form, PHP action checks the database. If 0, then redirect to fillable form. If 1, redirect to read-only form.

Thanks :-)