void __fastcall TForm1::Button1Click(TObject *Sender)
{
HANDLE event=CreateEvent(0,false,true,0);
HANDLE fil=CreateFile("a:\\temp.txt",GENERIC_WRITE,FILE_SHARE_WRITE,NULL,OPEN_EXISTING,FILE_FLAG_NO_BUFFERING|FILE_FLAG_OVERLAPPED,NULL);
char buf[90000];
OVERLAPPED over;
over.hEvent=event;
strcpy(buf,Form1->Memo1->Text.c_str());
DWORD out;
DWORD err;
DWORD res;
WriteFile(fil,buf,90000,NULL,&over);

}