20 PRINT CHR$(147):PRINT:PRINT
30 PRINT"ENTER A DATE (MM/DD/YYYY):";:INPUT"";A$
40 MN= VAL(LEFT$(A$,2)):DY= VAL(MID$(A$,4,2)):YR= VAL(RIGHT$(A$,4))
50 IF MN<1 OR MN>12 THEN90
60 M= VAL(MID$(MD$,(MN-1)*2+1,2))
70 IF DY<1 OR DY>M THEN90
80 IF YR<1 OR YR>2300 THEN 90
85 RETURN
90 PRINT:PRINT"INVALID DATE":PRINT:GOTO30
999 END