A contributor to and participant in the annuity and benefit fund provided for employees of such county, who resigns or is discharged from the county service, and thereafter is employed by the district, shall, upon the date of entering the employ of the district, become a contributor to and participant in the fund, with the same status he would have had in the county annuity and benefit fund if he had become a re-entrant into the service of the county on that date. The board shall transfer all sums to his credit in the county annuity and benefit fund to the fund, to be used therein for his benefit. The employee shall thereupon cease to have any rights in the county annuity and benefit fund.
40 ILCS 5/10-105