Creating an user from the backend using the API

DECLARE
  v_session_id INTEGER := userenv('sessionid');
 v_user_name  VARCHAR2(30) := upper('USERNAME');
BEGIN
  fnd_user_pkg.createuser(x_user_name=> v_user_name
    ,x_owner                      => ''
    ,x_unencrypted_password       => 'PASSWORD'
    ,x_session_number             => v_session_id
    ,x_start_date                 => SYSDATE - 10
    ,x_end_date                   => SYSDATE + 2000
    ,x_last_logon_date            => SYSDATE - 10
    ,x_description                => 'New user from backend'
    ,x_password_date              => SYSDATE - 10
    ,x_password_accesses_left     => 10000
    ,x_password_lifespan_accesses => 10000
    ,x_password_lifespan_days     => 10000
    ,x_email_address => ''
    ,x_fax           => ''
    ,x_customer_id   => ''
    ,x_supplier_id   => '');
  fnd_user_pkg.addresp(username       => v_user_name
                      ,resp_app       => 'SYSADMIN'
                      ,resp_key       => 'SYSTEM_ADMINISTRATOR'
                      ,security_group => 'STANDARD'
                      ,description    => 'Auto Assignment'
                      ,start_date     => SYSDATE - 10
                      ,end_date       => SYSDATE + 2000);
END;
/