document.getElementById('form').addEventListener('submit', function(e) {
    e.preventDefault();

    let data = new FormData(this);

    let xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
        console.log(this.response);
        if (this.readyState == 4 && this.status == 200) {
        } else if (this.readyState == 4) {
            alert('uhe erreur est survenue...');
        }
    };
    xhr.open('POST', 'cible/search.php', true);
    xhr.send(data);
    let p = document.createElement('p');
    p.textContent = 'hzllo';
    document.getElementById('corps').appendChild(p);
});