AcquireSourceName example for C++ Builder

void __fastcall TForm1::Button1Click(TObject *Sender) 
{
   int nRet; 

   LEADTwain1->AcquireSourceName = "TWAIN Source Name";
   nRet= LEADTwain1->Acquire (LTWAIN_SHOW_USER_INTERFACE); 
   if(nRet != SUCCESS) 
      ShowMessage("Error acquiring from source");
}