<?php 

function refreshDragableBox(uniqueIdentifier)

    {

        // var numericId = this.id.replace(/[^0-9]/g,''); - on supprime cette ligne

        var xhr_object = null;

        xhr_object = new XMLHttpRequest();  

        xhr_object.open("GET", 'page/' + uniqueIdentifier + '.php', false);

        xhr_object.send(null);

        var dragableBoxContentId = "dragableBoxContent" + numericId;

        document.getElementById(dragableBoxContentId).innerHTML = xhr_object.responseText;

    }