What was found
LEADING EDGE SLAT DISAGREE CAUTION MESSAGE APPEARED WHEN FLAPS WERE SELECTED FROM ZERO TO ONE. WE DECLARED AN EMERGENCY OUT OF AN ABUNDANCE OF CAUTION. RAN THE QRH FOR THE PROCEDURE. THE SLATS WERE RESTORED IN THE ALTERNATE MODE. LANDING UNEVENTFUL AT FLAPS 20. EMERGENCY DECLARED. T/S PER FIM 27-51 FT 809. BITE CHK OF FSEU SHOWS NO CURRENT FAULTS. LAST FLT LEG FAULTS LE SLATS MSG NO. 27-81045. FAULT INDICATES LE SLATS DISAGREE WITH FLAP HANDLE POSITION. A/C AHM REPORTS FLAP HANDLE NOT IN DETENT. AHM ATTACHED TO WRITE-UP. PERFORMED LE SLAT SYSTEM OPS CHK PER ABOVE AMM, NO FAULTS NOTED WITH NO MESSAGES. NO HISTORY LAST 90 DAYS. SDR SUBMIITTED BY MOCC. A/C OK FOR SERVICE.