I need to be able to upload a file to a case but keep getting 4600.

The following is the code.

Any help would be greatly appreciated.

2. <?php
3. $recordId="my-record-id";
4. $ch=curl_init();
5. curl_setopt($ch,CURLOPT_HEADER,0);
6. curl_setopt($ch,CURLOPT_VERBOSE,0);
7. curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
8. curl_setopt($ch,CURLOPT_URL,"https://crm.zoho.com/crm/private/xml/Cases/uploadFile?authtoken=<my-token>&scope=crmapi");
9. curl_setopt($ch,CURLOPT_POST,true);
10. $post=array("id"=>$recordId,"content"=>"/Users/john/files/filename.jpg");
11. curl_setopt($ch,CURLOPT_POSTFIELDS,$post);
12. $response=curl_exec($ch);
13. echo $response;
14. ?>