The employer properly computed overtime pay in accordance for pay periods in which it paid plaintiff an hourly wage and a percentage bonus on sales. The employer used the method prescribed for FSLA overtime (29 CFR 778.210), applying instead the DLSE’s Enforcement Manual method (section 49.2.4) would result in an improper overtime on overtime since the bonus already was computed as a percentage of the overtime calculated on the employee’s regular hourly wages.