E2451 Undefined symbol 'PaintBox1'

//---------------------------------------------------------------------------
 
#include <vcl.h>
#include <stdlib.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
const int scope = 10;
const int x0 = 1;
const int y0 = 1;
const int wight = 47;
const int height = 29;
int age = 0;
int field[height][wight];
 
void DrawCell(int x, int y)
{
    PaintBox1->Canvas->Pen->Color = clGreen; /// на это ругается
    PaintBox1->Canvas->Rectangle(x0+(x-1)*scope, y0+(y-1)*scope, x0+x*scope-1, y0+y*scope-1);
}
 
void CleanField()
{
    for(int i = 0; i < height; i++)
        for(int j = 0; j < wight; j++)
            field[height][wight] = 0;
}
 
void DrawField()
{
 
}
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
PaintBox1->Canvas->Pen->Color = clGray;
PaintBox1->Canvas->MoveTo(0, 0);
for(int i = 0; i < PaintBox1->Width; i+=scope)
{
    PaintBox1->Canvas->LineTo(i, PaintBox1->Height);
    PaintBox1->Canvas->MoveTo(i+scope, 0);
}
PaintBox1->Canvas->MoveTo(0, 0);
for(int i = 0; i < PaintBox1->Height; i+=scope)
{
    PaintBox1->Canvas->LineTo(PaintBox1->Width, i);
    PaintBox1->Canvas->MoveTo(0, i+scope);
}
}
//---------------------------------------------------------------------------
void __fastcall TForm1::PaintBox1MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
 
 
int x = X / scope + x0;
int y = Y / scope + y0;
Label1->Caption = x;
Label2->Caption = y;
if(field[x-1][y-1] == 0)
{
    DrawCell(x, y);
    field[x-1][y-1] = 1;
}
else
{
    PaintBox1->Canvas->Pen->Color = clMenu;
    PaintBox1->Canvas->Rectangle(x0+(x-1)*scope, y0+(y-1)*scope, x0+x*scope-1, y0+y*scope-1);
    field[x-1][y-1] = 0;
}
}
//---------------------------------------------------------------------------
 
 
 
 
void __fastcall TForm1::FormCreate(TObject *Sender)
{
    CleanField();
}
//---------------------------------------------------------------------------

void DrawCell(TCanvas *canvas, int x, int y)
{
    canvas->Pen->Color = clGreen; /// на это уже не ругается
    canvas->Rectangle(x0+(x-1)*scope, y0+(y-1)*scope, x0+x*scope-1, y0+y*scope-1);
}

void __fastcall TForm1::PaintBox1MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
TPaintBox *pb = static_cast<TPaintBox*>(Sender);
 
int x = X / scope + x0;
int y = Y / scope + y0;
Label1->Caption = x;
Label2->Caption = y;
if(field[x-1][y-1] == 0)
{
    DrawCell(pb->Canvas, x, y); // <--- !!!
    field[x-1][y-1] = 1;
}
else
{
    pb->Canvas->Pen->Color = clMenu;
    pb->Canvas->Rectangle(x0+(x-1)*scope, y0+(y-1)*scope, x0+x*scope-1, y0+y*scope-1);
    field[x-1][y-1] = 0;
}
}