[NumLock]

Код:

uses
  IdMultipartFormData, IdHTTP,

var
  AIdMultiPartFormDataStream: TIdMultiPartFormDataStream;
begin
  AIdMultiPartFormDataStream:=TIdMultiPartFormDataStream.Create;
  try
    AIdMultiPartFormDataStream.AddFormField('addtype', 'main'');
    AIdMultiPartFormDataStream.AddFormField('name', 'Алексей');
    AIdMultiPartFormDataStream.AddFormField('***', '***');
    AIdMultiPartFormDataStream.AddFormField('***', '***');
    AIdMultiPartFormDataStream.AddFormField('***', '***');
    // ..
    IdHTTP1.Post('http://server.domain', AIdMultiPartFormDataStream);
  finally
    AIdMultiPartFormDataStream.Free;
  end;
end;