URL encoding/decoding

uses
  httpprotocol;
var
  A, B: string;
begin
  A := 'http://www.somesite.com/page1.asp?id=65';
  B := HTTPEncode(A);
  A := HTTPDecode(B);

function EncodeUrl(const url: string): string;
var
  x: integer;
  sBuff: string;
const
  SafeMask = ['A'..'Z', '0'..'9', 'a'..'z', '*', '@', '.', '_', '-'];
begin
  //Init
  sBuff := '';

  for x := 1 to Length(url) do
  begin
    //Check if we have a safe char
    if url[x] in SafeMask then
    begin
      //Append all other chars
      sBuff := sBuff + url[x];
    end
    else if url[x] = ' ' then
    begin
      //Append space
      sBuff := sBuff + '+';
    end
    else
    begin
      //Convert to hex
      sBuff := sBuff + '%' + IntToHex(Ord(url[x]), 2);
    end;
  end;

  Result := sBuff;
end;

function DecodeUrl(const url: string): string;
var
  x: integer;
  ch: string;
  sVal: string;
  Buff: string;
begin
  //Init
  Buff := '';
  x := 1;
  while x <= Length(url) do
  begin
    //Get single char
    ch := url[x];

    if ch = '+' then
    begin
      //Append space
      Buff := Buff + ' ';
    end
    else if ch <> '%' then
    begin
      //Append other chars
      Buff := Buff + ch;
    end
    else
    begin
      //Get value
      sVal := Copy(url, x + 1, 2);
      //Convert sval to int then to char
      Buff := Buff + char(StrToInt('$' + sVal));
      //Inc counter by 2
      Inc(x, 2);
    end;
    //Inc counter
    Inc(x);
  end;
  //Return result
  Result := Buff;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  A, B: string;
begin
  A := 'http://www.somesite.com/page1.asp?id=65';
  //Encode url
  B := EncodeUrl(A);
  //Show Encoded url
  ShowMessage(B);
  //Show deoded url
  ShowMessage(DecodeUrl(B));
end;