plot顯示N/A

我利用以下腳本跑台股指數期貨近月

用Print 能顯示我要的結果，但試著用PLOT做指標試著顯示部分卻顯示N/A

variable: I(0),B(0),S1(0),S2(0),S3(0),S4(0),S5(0),S1V(0), S2V(0), S3V(0), S4V(0),S5V(0);
settotalbar(40);
if date = currentdate then 
begin
For B= 1 to 40 begin
if high[B] > close[0] and high[B] >high[0] and I <=40 then
  begin
S1=high[B];
S1V=volume[B];
  I = B;
break;end;
 end;
 For B= I to 40 begin
     If high[B]>S1 and I <=40 then
  begin
S2= high[B];
  S2V= volume[B];
  I=B;
  break;end;
end;
 For B= I to 40 begin
     If high[B]>S2 and I<=40 then
  begin
S3= high[B];
  S3V= volume[B];
  I=B;
  Break;end;
end;
 For B= I to 40 begin
     If high[B]>S3 and I <=40 then
  begin
S4= high[B];
  S4V= volume[B];
  I=B;
  Break;end;
end;
 For B= I to 40 begin
     If high[B]>S4 and I<=40 then
  begin
S5= high[B];
  S5V= volume[B];
  I=B;
  Break;end;
end;
end;
//print(date,S1,S1V,S2,S2V,S3,S3V,S4,S4V,S5,S5V,I);
Plot1(S1);
Plot2(S2);