This email form is setup to work with Mail Chimp API ... all that is needed to make it work with another Mail Chimp Account is to:
1. update URL in the form action
2. make sure the merge field names align with the Mail Chimp account being targeted
3. update the validation script located immediately below the submit button.
There is custom form validation setup that requires first name, last name and email to contain values and for the email to comply with a standard email pattern. If these conditoins are not met, then the submit button will remain disabled. Satisfying these requirements will enable the button. Form fields are also styled with color for visual feedback that updates on blur (tab of clicking out of a field).
When a user closes the popup form, a cookie is set that will remain in effect for 24 hours, preventing the window from showing again. This is done for a better user experience. If the user wishes to see the form again, they can click the "show form" button which will remove the cookie and show the form.
If a user successfully submits the form a cookie is set for 30 days that prevents the form from showing.