30000 REM  QUICKSORT -----------------------------------------------------------
30001 DIMLG(100),RG(100):Z=0:LG(1)=1:RG(1)=SZ
30010 Z=Z+1:IFLG(Z)>=RG(Z)THEN30120
30020 X=LG(Z):Y=RG(Z)
30030 VG$=D$(INT((X+Y)/2))
30040 IF X>Y THEN30100
30050 IF D$(X)<VG$THENX=X+1:GOTO30050
30060 IF D$(Y)>VG$THENY=Y-1:GOTO30060
30070 IF X>YTHEN30100
30080 S$=D$(X):D$(X)=D$(Y):D$(Y)=S$
30090 X=X+1:Y=Y-1:GOTO30040
30100 RG(Z+1)=Y:LG(Z+1)=LG(Z):GOSUB30010
30110 LG(Z+1)=X:RG(Z+1)=RG(Z):GOSUB30010
30120 Z=Z-1:RETURN