function getGAClientID() {
let match = document.cookie.match(/_ga=([^;]*)/);
return match ? match[1].split('.').slice(-2).join('.') : null;
}
document.addEventListener("DOMContentLoaded", function() {
let clientID = getGAClientID();
if (clientID) {
document.getElementById('client_id').value = clientID;
}
});