Проблемма с типом данных или кодировкой

#include <vcl.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
 
#include <iostream.h>
#include <cctype>
#include <tchar.h>
#include <conio.h>
#include <stdio.h>
using namespace std;
 
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
 
 
}
//---------------------------------------------------------------------------
void __fastcall TForm1::Button1Click(TObject *Sender)
{
int i;
 char str[80]; // = "This Is A Text";
 
Edit1->Text=str;
 for (i = 0; str[i]; i++) {
    if (isupper (str[i]))
      str[i] = tolower (str[i]);
    else if (islower (str[i]))
      str[i] = toupper (str[i]);
}
 
 
Label1->Caption=str;
 
 
 
 
}

//---------------------------------------------------------------------------
 
void __fastcall TForm1::Edit1Change(TObject *Sender)
{
Label1->Caption = ("" + (Edit1->Text));        
}
//---------------------------------------------------------------------------

Edit1->Text=str;

str = Edit1->Text.c_str();
/*
AnsiString etxt = Edit1->Text;
str = etxt.c_str();
*/