biểu đồ cột trong PASCAL

uses crt,Graph;
var Gd,Gm,i,max: integer;
a: array[1..5] of word;
tl: real;
pattern : FillPatternType;
begin
write('nhap 5 so tu nhien:');
for i:=1 to 5 do read (a[i]);
readln;
max:= a[1];
for i:=2 to 5 do if Max < a[i] then Max:= a[i];
tl:= 300/max;
Gd:= detect;
initGraph (Gd,Gm,' ');
GetFillPattern (Pattern);
for i:=1 to 5 do
begin
SetFillPattern (Pattern,i);
bar (i*30+100,400,i*30+120,round (400-a[i]*tl));
end;
readln;
closegraph;
end.