How to make sure that the desired page id is saved in cookies?

Question

JavaScript

Tell me how to make it so that the page id is recorded in the cookie, and not the id that is specified in javascript

function add2note()
{
  function str_replace(search, replace, subject) { return subject.split(search).join(replace);}
var button = document.getElementById('addnotepage');
var Link2Note = document.getElementById('Link2Note');
var count_note_message = 0;
var id = 1001000;
var fid = 2;
value = fid+"i"+id+"s";
var cookies = getCookie("BoardNote");
if (cookies == undefined) cookies = "";

var id = 1001000 - here is the id itself, what to write so that it takes id from this field ( prntscr.com/hnd2xt prntscr.com/hnd37b)