Anyone knows if it's possible to do the following:
When a person keys in his email address in the Marketo landing page form:
- If his email address is already in the Marketo list relevant to the landing page form, he will receive an on-site message saying "he has already signed up"
- If his email address is not in the list, then he will go through the standard form submission process.
This will have to happen live. Any developers here who can point me in the right direction. What do you think I have to do to make this work?