Error creating table (Error in your sql syntax). What am I doing wrong?
CREATE TABLE Customer ( Customer_ID INTEGER(8) PRIMARY KEY, f_Name VARCHAR(25) NOT NULL, l_Name VARCHAR(25) NOT NULL);

CREATE TABLE Users ( Manager_ID INTEGER(8) NOT NULL, Employee_ID INTEGER(8) NOT NULL, f_Name VARCHAR(25) NOT NULL, l_Name VARCHAR(25) NOT NULL,
    CONSTRAINT Users_Manager_ID_PK PRIMARY KEY(Manager_ID, Employee_ID),
    CONSTRAINT idx_unque_users UNIQUE KEY (Employee_ID,Manager_ID));

CREATE TABLE Advertising ( Sales_Person VARCHAR(25) PRIMARY KEY, Manager_ID INTEGER(8) NOT NULL,Employee_ID INTEGER(8) NOT NULL,
    CONSTRAINT Advertising_Manager_ID_FK FOREIGN KEY (Manager_ID) REFERENCES Users(Manager_ID), 
    CONSTRAINT Advertising_Employee_ID_FK FOREIGN KEY (Employee_ID) REFERENCES Users(Employee_ID));