How can i upload a file using ZOHO CRM V2 to my image file upload Fields?

How can i upload a file using ZOHO CRM V2 to my image file upload Fields?

Please help me in uploading a image file to my Zoho CRM (Potentials) with custom layout using ZOHO CRM API V2 .
I am inserting all text data using ZOHO CRM API V2 but facing problem in uploading a files to  custom File upload fields .

Thanks