. Copiar um arquivo de um lugar para outro

Procedure CopyFile( Const sourcefilename, targetfilename: String );
Var S, T: TFileStream;
Begin
S := TFileStream.Create( sourcefilename, fmOpenRead );
try
T := TFileStream.Create(targetfilename,fmOpenWrite or fmCreate);
try
T.CopyFrom(S, S.Size ) ;
finally
T.Free;
end;
finally
S.Free;
end;
end;