check if record exists

I am the newest of new to PHP and am just starting to code my first project.

I have a database (db_code) with a single table (tbl_code) with 1000 records of 8 digits. something like DHYHGTYF, SBEYFISN etc.

All i wish to do is create a form which a user enters a code that they have been given (one of the 8 digit codes). If it matches go to web page one, if they enter a code with does NOT exist then go to web page 2.

I guess a bit like a login form but only uses one field.... a code field.

Could anyone help me with some syntax?

UKD.