Access violation at address in module. Read of address

#include <vcl.h>
#include <time.h>
#include <stdlib.h>
#pragma hdrstop
#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
int base=10,dig=0;
bool flag=false;
char *prew = new char[33];
//clock_t t=0;
 
HINSTANCE dllinstance;
typedef char *(__import * FType(char*,TForm *));
typedef char *(__import * FType2(Char*,int, int));
FType * init;
FType2 * conv[100];
 
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
 
 
void __fastcall TForm1::OnIdle(TObject *Sender, bool &Done)
{
}
//---------------------------------------------------------------------------
void ListFiles(AnsiString path, TStrings* List)
{
// Эта процедура выводит список файлов и вызывает
// саму себя для всех каталогов
  TSearchRec sr;
  if (FindFirst(path+"*.*", faAnyFile, sr) == 0)
  {
    do
    {
      if ((sr.Attr & faDirectory)&&(sr.Name!=".")&&(sr.Name!=".."))
        ListFiles(path+sr.Name+"", List); // Рекурсивный вызов
      else
      {
        AnsiString Ext=ExtractFileExt(sr.Name).UpperCase();
        if (Ext==".DLL")
          List->Add(path+sr.Name);
      }
    }
    while (FindNext(sr) == 0);
    FindClose(sr);
  }
  Application->ProcessMessages();
}
 
 
 
void __fastcall TForm1::FormCreate(TObject *Sender)
{
  TStringList *files = new TStringList;
  ListFiles(".\\plugins",files);
  TForm *form = Form1;
  char *mode = new char[3];
  int col=0;
  for(int i= 0; i<files->Count;i++)
  {
    dllinstance=LoadLibrary(files->Strings[i].c_str());
    if (dllinstance)
    {
      init=(FType*)GetProcAddress(dllinstance, "_init");
      if (init)
      {
        init(mode,form);
        if (isdigit(*mode))
          if (conv[atoi(mode)]==NULL)
          {
            col++;
            conv[atoi(mode)]=(FType2*)GetProcAddress(dllinstance, "_convert");
          }
      }
      init=NULL;
      dllinstance=NULL;
    }
  }
    //StatusBar1->Panels->Items[1]->Text=(AnsiString)col;
    delete [] mode;
 
    Application->OnActivate=OnActivate;
    Application->OnDeactivate=OnDeactivate;
  
  }
//---------------------------------------------------------------------------
void __fastcall TForm1::RadioGroup1Click(TObject *Sender)
{           //Время в мс и в сут.
   int a;
   base=atoi(RadioGroup1->Items->Strings[RadioGroup1->ItemIndex].c_str());
   char * buf = new char[33],
        * s = new char[33];
   unsigned num,k=0,er;
   strcpy(s,Edit1->Text.c_str());
   for(unsigned i=0;i<strlen(s);i++)
   {
     er=0;
     if((base<=10)&&(!isdigit(s[i])||(s[i]-'0'>base-1))) er=1;
      else  if((toupper(s[i])>'A'+base-11)||((toupper(s[i])<'A')&&(toupper(s[i])>'9'))) er=1;
     if (!er)
     {
       buf[k]=s[i];
       k++;
     }
   }
   delete []s;
   buf[k]='\0';
   Edit1->Text=buf;
   if (conv[base]!=NULL)
    buf= (char*)conv[base](buf,10,base);
   Edit2->Text=(AnsiString)buf;
   delete [] buf;
   //StatusBar1->Panels->Items[4]->Text=(AnsiString)(clock()-t)+" мс.";
   //StatusBar1->Panels->Items[5]->Text=(AnsiString)((clock()-t)/1000.0/60/60/24)+" сут.";
   //t=clock();
}
//---------------------------------------------------------------------------
 
 
void __fastcall TForm1::RadioGroup1Enter(TObject *Sender)
{
  if (RadioGroup1->ItemIndex>-1)
    RadioGroup1Click(Sender);
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Edit1KeyPress(TObject *Sender, char &Key)
{
  if((Key!=13)&&(Key!=9)&&(Key!=8))
    if((base<=10)&&(!isdigit(Key)||(Key-'0'>base-1)))Key=0;
    else  if((toupper(Key)>'A'+base-11)||((toupper(Key)<'A')&&(toupper(Key)>'9')))Key=0;
  if ((Key==13)&&(RadioGroup1->ItemIndex>-1)) RadioGroup1Click(Sender);
 
}

#include <vcl.h>
#include <windows.h>
#include<string>
#pragma hdrstop
#pragma argsused
#include "dllconv.h"
int WINAPI DllEntryPoint(HINSTANCE hinst, unsigned long reason, void* lpReserved)
{
        return 1;
}
//---------------------------------------------------------------------------
 
char* init(char*s,TForm * form)
{
  TRadioGroup* rg=((TRadioGroup*)form->Components[2]);
  int id =  rg->ItemIndex;
  rg->Items->Add("16");
  rg->ItemIndex=id;
  form->Height+=40;
  strcpy(s,"16");
}
 
char * convert(char * s,int base, int prew)
{
   char * buf,*r;
   unsigned num=0;
   r=s;
   while (*r)
   {
     num=isdigit(*r)?(num*16+(*r++)-'0'):(num*16+toupper(*r++)-'A'+10);
   }
   delete [] s;
   r= new char[33];
   strcpy(r,IntToStr(num).c_str());
   strcat(r,"");
   return r;
}