function retrieve_ts(url: string; xstart: string; xend: string):integer; external 'ytrf_retrieve_ts@maps\YaTraf.dll stdcall';
function GetIntParam(key: string): Integer; external 'ytrf_GetIntParam@maps\YaTraf.dll stdcall';
function SetIntParam(key: string; val: Integer): integer; external 'ytrf_SetIntParam@maps\YaTraf.dll stdcall';
function GetUTS: Longint; external 'ytrf_GetUTS@maps\YaTraf.dll stdcall';

function ts_update_needed(delta: integer):integer;
var
  lts, ts : integer;
  lts_key: string;
begin
  result:=0;
  lts_key:='ytrf_lts';
  lts:=GetIntParam(lts_key);
  ts:=GetUTS;
  if (ts>lts+delta) then begin
    SetIntParam(lts_key, GetUTS);
    result:=1;
  end;
end;

function get_ts(delta: integer):integer;
var
  ts_key, url, data: string;
  pt : LongInt;
begin
 result:=0;
 ts_key:='ytrf_ts';
 if (ts_update_needed(delta)>0) then begin
   url:='http://trf.maps.yandex.net/trf/stat.js';
   result:=retrieve_ts(url, 'timestamp:"', '"');
   SetIntParam(ts_key, result);
 end else begin
   result:=GetIntParam(ts_key);
 end;
end;

begin
 ResultURL:='';
 if (GetZ<>0) then ResultURL:=GetURLBase+inttostr(GetX)+'&y='+inttostr(GetY)+'&z='+inttostr(GetZ-1)+'&tm='+inttostr(get_ts(60));
end.