Kodowanie cezara ( Linker error )

 Unit1.cpp

//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include "Unit2.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)
{
if(OpenDialog1->Execute()){
        Memo1->Lines->LoadFromFile(OpenDialog1->FileName);
        }
        Memo2->Clear();
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button2Click(TObject *Sender)
{
if(SaveDialog1->Execute()){
        Memo1->Lines->SaveToFile(SaveDialog1->FileName);
        }
}
//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
int TForm1::IleZnakow(){
        int znaki=0;
        if(Memo1->Lines->Count>0){
                for(int i=0;i<Memo1->Lines->Count;i++)
                znaki+=Memo1->Lines->Strings[i].Length();
                }
        return znaki;
}
bool TForm1::CzySamogloska(char znak){
        char samogloski[5] = {'a','e','i','o','u'};
        for(int i=0;i<5;i++)
        if(znak==samogloski[i] || znak==UpCase(samogloski[i]))
        return true;
        return false;
        }
int TForm1::IleSamoglosek(){
        int ile=0;
        for(int i=0;i<Memo1->Lines->Count;i++){
                for(int  j=1;j<=Memo1->Lines->Strings[i].Length();j++)
                if(CzySamogloska(Memo1->Lines->Strings[i][j]))
                        ile++;
                        }

                return ile;
        }
void __fastcall TForm1::Button3Click(TObject *Sender)
{
 if (Memo2->Lines->Count>0){
             Memo1->Clear();
        int klucz=StrToInt(edKlucz->Text);
        Cezar c1(-klucz);
        for (int i=0;i<Memo2->Lines->Count;i++){
                Memo1->Lines->Add(c1.Koduj(Memo2->Lines->Strings[i]));
        }
        }else ShowMessage("Brak Tekstu");
}
//---------------------------------------------------------------------------
   bool TForm1::CzyLitera(char znak){
   if(znak>='a' && znak<='z')return true;
   if(znak>='A' && znak<='Z')return true;
   return false;
   }
//_________________
int TForm1::IleLiter(){
int licznik=0;
if (Memo1->Lines->Count>0){
        String linia;
        for(int i=0; i<Memo1->Lines->Count;i++){
        linia= Memo1->Lines->Strings[i]; 
        for(int j=1;j<linia.Length();j++){
                if (CzyLitera(linia[j]))licznik++;
        }
}
}return licznik;
}
void __fastcall TForm1::btnKodujClick(TObject *Sender)
{
        if (Memo1->Lines->Count>0){
             Memo2->Clear();
        int klucz=StrToInt(edKlucz->Text);
        Cezar c1(klucz);
        for (int i=0;i<Memo1->Lines->Count;i++){
                Memo2->Lines->Add(c1.Koduj(Memo1->Lines->Strings[i]));
        }
        }else ShowMessage("Brak Tekstu");
}
void __fastcall TForm1::Button6Click(TObject *Sender)
{
if (Memo2->Lines->Count>0 )   {
        if(SaveDialog2->Execute()){
              Memo2->Lines->SaveToFile(SaveDialog2->FileName);
        }
}
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Button7Click(TObject *Sender)
{
if(OpenDialog2->Execute()){
        Memo2->Lines->LoadFromFile(OpenDialog2->FileName);
        }
Memo1->Clear();        
}
//---------------------------------------------------------------------------


void __fastcall TForm1::Label1Click(TObject *Sender)
{
        
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Panel2Click(TObject *Sender)
{

}
//---------------------------------------------------------------------------


Unit2.cpp


//---------------------------------------------------------------------------
#pragma hdrstop
#include "Unit2.h"
//---------------------------------------------------------------------------
const int ILELITER=26;
#pragma package(smart_init)
Cezar::Cezar(int klucz){
        this->klucz=klucz %ILELITER;
}
 bool Cezar::CzyLitera(char znak){
   if(znak>='a' && znak<='z')return true;
   if(znak>='A' && znak<='Z')return true;
   return false;

 }
 char Cezar::KodujZnak(char znak){
        char wynik;
        if (CzyLitera(znak)) {
        wynik= znak+klucz;
        if(!CzyLitera(wynik))wynik=ILELITER;
        }
        else wynik =znak;
        return  wynik;
 }

String Cezar::Koduj(String linia){
String wynik=linia;
for (int i=1; i<=linia.Length();i++)  {
        wynik[i]=KodujZnak(linia[i]);   
        }
        return wynik;
}


Unit1.h

//---------------------------------------------------------------------------
#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>
#include <ExtCtrls.hpp>
#include <Dialogs.hpp>
#include <ComCtrls.hpp>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
        TPanel *Panel1;
        TMemo *Memo1;
        TPanel *Panel2;
        TMemo *Memo2;
        TOpenDialog *OpenDialog1;
        TSaveDialog *SaveDialog1;
        TButton *Button1;
        TButton *Button2;
        TButton *btnKoduj;
        TEdit *edKlucz;
        TUpDown *UpDown1;
        TOpenDialog *OpenDialog2;
        TSaveDialog *SaveDialog2;
        TButton *Button6;
        TLabel *Label11;
        TButton *Button3;
        TButton *Button7;
        TLabel *Label1;
        TLabel *Label2;
        void __fastcall Button1Click(TObject *Sender);
        void __fastcall Button2Click(TObject *Sender);
        void __fastcall Button3Click(TObject *Sender);
        void __fastcall btnKodujClick(TObject *Sender);
        void __fastcall Button6Click(TObject *Sender);
        void __fastcall Button7Click(TObject *Sender);
private:
        int IleZnakow();
        int IleLiter();
        bool CzySamogloska(char znak);
        int IleSamoglosek();
        bool CzyLitera(char znak);
       
public:		// User declarations
        __fastcall TForm1(TComponent* Owner);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

Unit2.h

//---------------------------------------------------------------------------
#ifndef Unit2H
#define Unit2H
#include <vcl.h>
class Cezar{
        private:
                int klucz;
                bool CzyLitera(char znak);
                char KodujZnak(char znak);
        public:
                Cezar(int klucz);
                String Koduj(String linia);
};
//---------------------------------------------------------------------------
#endif