исправить ошибки

program ddd;
uses crt, GraphABC;
var drivervar, modevar, errcode,a4, a3, b4, b3, c1, dx, dy:integer;
x1,x2,y1,y2,d,t:real;
play: boolean;
begin
drivervar:=detect;
initgraph (drivevar, modevar, '');
repeat
if random (5)=0 then play:=true else play:=false;
setfillstyle (1, white);
bar (0,0, getmaxx, getmaxy);
setcolor (0);
a4:=random(5); a3:=random(5); b4:=random(5);
b3:=random(5); c1:=random (5)*2;
t:=0;
setcolor (random(4));
repeat;
if play and (random(5)=1) then setcolor (random(14));
d:=t+c1;
x1:=(1.5*cos(a4*t)+1.5*cos(a3*2*t))*60;
x2:=(1.5*cos(a4*d)+1.5*cos(a3*2*d))*60;
y1:=(1.5*sin(b4*t)+1.5*sin(b3*2*t))*60;
y2:=(1.5*sin(b4*d)+1.5*sin(b3*2*d))*60;
dx:=getmaxx div 2; dy:=getmaxy div 2;
line (round(y1)+dx,round(x1)+dy,round(x2)+dx,round(y2)+dy);
t:=t+0.01;
until (t>=5);
setcolor(15);
delay(500);
until keypressed;
closegraph;
end.

program ddd;
 
uses
  crt, Graph;
 
var
  driver, modevar, errcode, a4, a3, b4, b3, c1, dx, dy: integer;
  x1, x2, y1, y2, d, t: real;
  play: boolean;
 
begin
  driver := detect;
  initgraph(driver, modevar, '');
  repeat
    if random(5) = 0 then play := true else play := false;
    setfillstyle(1, white);
    bar(0, 0, getmaxx, getmaxy);
    setcolor(0);
    a4 := random(5); a3 := random(5); b4 := random(5);
    b3 := random(5); c1 := random(5) * 2;
    t := 0;
    setcolor(random(4));
    repeat ;
      if play and (random(5) = 1) then setcolor(random(14));
      d := t + c1;
      x1 := (1.5 * cos(a4 * t) + 1.5 * cos(a3 * 2 * t)) * 60;
      x2 := (1.5 * cos(a4 * d) + 1.5 * cos(a3 * 2 * d)) * 60;
      y1 := (1.5 * sin(b4 * t) + 1.5 * sin(b3 * 2 * t)) * 60;
      y2 := (1.5 * sin(b4 * d) + 1.5 * sin(b3 * 2 * d)) * 60;
      dx := getmaxx div 2; dy := getmaxy div 2;
      line(round(y1) + dx, round(x1) + dy, round(x2) + dx, round(y2) + dy);
      t := t + 0.01;
    until (t >= 5);
    setcolor(15);
    delay(500);
  until keypressed;
  closegraph;
end.