This depends on what you are doing. Are you trying to add a new contact? If you are, then the URI you would be sending to would be "https://api.constantcontact.com/ws/customers/username/contacts" and you would not have anything after contacts.
If you are updating or retreiving information on a specific contact, then the variable would be the contacts ID.
If you have any questions please let me know.
What are you trying to do with this URI? Are you doing a post, put, get, or delete? A 415 error usually means you are making an invalid type of HTTPS call to the uri. Such as trying to do a POST to a contacts ID.
If you are trying to add a contact to your account, you would do a POST to the https://api.constantcontact.com/ws/customers/username/contacts URI.
hello.... When we create a campaign we used '.$html.' for adding dynamic html content from the fckeditor for sending email. But it cause an error "Error 400: You must have content for your letter400" and the mail sending function failed. $html contains the data .If we hardcoded html in tags it works.
Thanks in advance
Are you HTML encoding the HTML inside of the variable? If you are not that is probably why it is failing.
If you are, then I would need to see your code to figure out exactly what is wrong. You could send it here and we will review it.