E2277 Lvalue required

char *str = grid->Cells[0][0].c_str(); //и тут ошибка

//---------------------------------------------------------------------------
 
#include <vcl.h>
#include <stdio.h>
#include <conio.h>
#pragma hdrstop
 
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TMainForm *MainForm;
//---------------------------------------------------------------------------
typedef struct
{
        char site[500];
        char email[500];
        char login[500];
        char pass[500];
        char about[500];
} Record;
//---------------------------------------------------------------------------
char *path = "pmdb.bin";
int count = 1;
Record *rec = new Record[count];
//HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
//---------------------------------------------------------------------------
bool Save(Record *rec, int *count, PCHAR path)
{
        FILE *fp = fopen(path, "wb");
        if (!fp) return false;
        int len;
        for(int i = 0; i < (*count); i++)
        {
                len = strlen(rec[i].site);
                fwrite(&len, sizeof(int), 1, fp);
                fwrite(rec[i].site, sizeof(char), len, fp);
                len = strlen(rec[i].email);
                fwrite(&len, sizeof(int), 1, fp);
                fwrite(rec[i].email, sizeof(char), len, fp);
                len = strlen(rec[i].login);
                fwrite(&len, sizeof(int), 1, fp);
                fwrite(rec[i].login, sizeof(char), len, fp);
                len = strlen(rec[i].pass);
                fwrite(&len, sizeof(int), 1, fp);
                fwrite(rec[i].pass, sizeof(char), len, fp);
                len = strlen(rec[i].about);
                fwrite(&len, sizeof(int), 1, fp);
                fwrite(rec[i].about, sizeof(char), len, fp);
        }
        fclose(fp);
        return true;
}
//---------------------------------------------------------------------------
bool Load(Record *rec, int *count, PCHAR path)
{
        FILE *fp = fopen(path, "rb");
        if (!fp) return false;
        int len;
        Record *tmp;
        while(!EOF)
        {
                fread(&len, sizeof(int), 1, fp);
                fread(rec[(*count)-1].site, sizeof(char), len, fp);
                fread(&len, sizeof(int), 1, fp);
                fread(rec[(*count)-1].email, sizeof(char), len, fp);
                fread(&len, sizeof(int), 1, fp);
                fread(rec[(*count)-1].login, sizeof(char), len, fp);
                fread(&len, sizeof(int), 1, fp);
                fread(rec[(*count)-1].pass, sizeof(char), len, fp);
                fread(&len, sizeof(int), 1, fp);
                fread(rec[(*count)-1].about, sizeof(char), len, fp);
                tmp = rec;
                rec = new Record[++(*count)];
                memcpy(rec, tmp, (*count)-1);
        }
        delete [] tmp;
        fclose(fp);
        return true;
}
//---------------------------------------------------------------------------
__fastcall TMainForm::TMainForm(TComponent* Owner)
        : TForm(Owner)
{
        grid->Cells[0][0] = "Site";
        grid->Cells[1][0] = "Email";
        grid->Cells[2][0] = "Login";
        grid->Cells[3][0] = "Password";
        grid->Cells[4][0] = "About";
        //path = GetEnvironmentVariable("");
        if (Load(rec, &count, path))
        {
                grid->RowCount = count + 1;
                for(int i = 1; i < grid->RowCount; i++)
                {
                        grid->Cells[0][i] = rec[i-1].site;
                        grid->Cells[1][i] = rec[i-1].email;
                        grid->Cells[2][i] = rec[i-1].login;
                        grid->Cells[3][i] = rec[i-1].pass;
                        grid->Cells[4][i] = rec[i-1].about;
                }
        }
}
//---------------------------------------------------------------------------
void __fastcall TMainForm::FormDestroy(TObject *Sender)
{
        if ((grid->RowCount == 2) &&
            (grid->Cells[0][0] == "") &&
            (grid->Cells[1][0] == "") &&
            (grid->Cells[2][0] == "") &&
            (grid->Cells[3][0] == "") &&
            (grid->Cells[4][0] == "")) return;
        count = grid->RowCount - 1;
        rec = new Record[count];
        for (int i = 1; i < grid->RowCount; i++)
        {
                rec[i-1].site = grid->Cells[0][i].c_str();
                rec[i-1].email = grid->Cells[1][i].c_str();
                rec[i-1].login = grid->Cells[2][i].c_str();
                rec[i-1].pass = grid->Cells[3][i].c_str();
                rec[i-1].about = grid->Cells[4][i].c_str();
        }
        AnsiString msg = "Save error!";
        if (!Save(rec, &count, path))
                Application->MessageBox(msg.c_str(),
                Application->Title.c_str(),
                MB_OK | MB_ICONERROR);
}
//---------------------------------------------------------------------------