通过HTTP-POST连接到Delphi应用程序的php脚本[通过Internet]

Question

I've written a test php script located in a remote server of mine, and I am using Delphi code to do a Http_Post to that php file.

It works perfectly when I am doing it on a local server, but fails with a

Socket Error #10061 - Connection Refused

error.

Here is the code I am using to do the Http Post :

function TForm1.doPost(Url : String): string;
var
  lHTTP: TIdHTTP;
  lParamList: TStringList;
begin
  lParamList := TStringList.Create;
  lParamList.Add('service_test=Testing Server');

  lHTTP := TIdHTTP.Create(nil);
  try
    Result := lHTTP.Post(Url, lParamList);
    prgView.StepIt;
  finally
    lHTTP.Free;
    lParamList.Free;
  end;
end;

The url is reachable fro, browser and other applications viz. [Tested with an android app with the same php script]

Url : http://pbcserver.dlinkddns.com/users/priyabrata/contest.php

Php Script :

if (isset($_POST["service_test"])){
    $val = $_POST["service_test"];
    if ($val == "Testing Server"){
        $response["Success"] = "1";
        echo (json_encode($response));
    }
    else{
        $response["Success"] = "0";
        echo (json_encode($response));
    }
}
else{
    $response["Success"] = "0";
    echo (json_encode($response));
}

New Observation :

When I run the app from within Delphi, the post doesn't work and get the above error,however when I run the created .exe from Windows like any other app, it works perfectly!