Self-increment in database, PHP mysql_query insert how to write

The self-increment in the database, PHP mysql_query insert how to write?
Database
Create Database umx;
Use UMX;
CREATE table if not exists umxtable (
UID Int (ten) unsigned NOT NULL Auto_increment primary key COMMENT ' uniquely marked ',
Email varchar (+) NOT null COMMENT ' e-mail '
) Auto_increment=1;

The Web page has only one input box, which is to enter an email.
In PHP, if you want to insert data, use mysql_query ("How do I write here?") "), I do not want to manually enter the UID, let it automatically increase on the can.


------to solve the idea----------------------
Landlord, with NULL to replace the value. VALUES (Null,[email protected])

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