Is it possible to make form entry dependent on a date field?

[Aledml]

We have a form that requires a contact's email, and a platform that requires that the same email is used throughout the sign-up process. Is it possible to throw an error on a form IF the email the contact is using is NOT connected to a certain field (i.e. Application Date)?

I have this resource, but am not adept at CSS: https://experienceleague.adobe.com/docs/marketo/using/product-docs/demand-generation/forms/form-desi...

[SanfordWhiteman]

What do you mean by "connected to"? The question isn't clear – please describe the form experience for the user.

[Vinay_Kumar]

You can use Validation rules or custom JS validation to throw an error based on the field. 

[SanfordWhiteman]

Vinay, I don't see how that answers the question given that there's not enough detail to begin with.

(In fact I know it doesn't answer it, given some information Alex provided in another channel!)