Ошибка Undefined symbol 'DllHandle'

if (OpenDialog1->Execute())
{
float N;
   N = StrToFloat(Edit2->Text);
 
   float pervaya[100] ;
   float vtoraya[100]  ;
   float tretya[100] ;
   float dl1[100];
 
   for(int i=0;i<N;i++)
{   pervaya[i]=StrToFloat(StringGrid1->Cells[0][i+1]) ;
    vtoraya[i]=StrToFloat(StringGrid1->Cells[1][i+1]) ;
    tretya[i]=StrToFloat(StringGrid1->Cells[2][i+1]);
}
 
   DllHandle=LoadLibrary(OpenDialog1->FileName.c_str());
   if(!DllHandle)
   {
        ShowMessage("Íåâîçìîæíî çàãðóçèòü dll");
        return;
   }
   if(DllHandle)
   {
 
   b0=(B0)GetProcAddress(DllHandle,"_b0");
   b1=(B1)GetProcAddress(DllHandle,"_b1");
   max1=(MAX1)GetProcAddress(DllHandle,"_max1");
 
  // Edit4->Text = b1(N, pervaya, vtoraya );
  // Edit5->Text = b0(N, pervaya, vtoraya );
 //  Edit6->Text = max1(N,  pervaya, vtoraya );
 
   NomerAp=(NOMERAP)GetProcAddress(DllHandle,"_NomerAp");
   int nomer= NomerAp();
   if (nomer==1) {
   N17->Visible=True;
   Form5->Show();
   Form5->Edit4->Text = b1(N, pervaya, vtoraya );
   Form5->Edit5->Text = b0(N, pervaya, vtoraya );
   Form5->Edit6->Text = max1(N,  pervaya, vtoraya );
 
   Form5->Edit1->Text = b1(N, pervaya, tretya);
   Form5->Edit2->Text = b0(N, pervaya, tretya );
   Form5->Edit3->Text = max1(N,  pervaya, tretya );
 
   }
    };
 
}

 HINSTANCE  DllHandle=LoadLibrary(OpenDialog1->FileName.c_str());