Problem in regestring new customers in when database has many customers

[neerajg27]

I am having problem in registering new customer. My database has more than 1000 registered users and more than 5000 products listed.

 

1062 - Duplicate entry '0' for key 'PRIMARY'

 

insert into customers (customers_firstname, customers_lastname, customers_email_address, customers_telephone, customers_fax, customers_newsletter, customers_password, customers_gender, customers_dob) values ('Neeraj', '[email protected]', '89898989', '89898989', '', '8a1379726286973f5ea1c7615c27ac4f:16', 'm', '19760527')