function obtenerCookie(clave) { var name = clave + "="; var ca = document.cookie.split(';'); for(var i=0; i<ca.length; i++) { var c = ca[i]; while (c.charAt(0)==' ') c = c.substring(1); if (c.indexOf(name) == 0) return c.substring(name.length,c.length); } return false; } var valueCookie = obtenerCookie('__lglaw'); console.log('afterBody_tag_lg_src ' +valueCookie); var afterBody_tag_lg_src = "//www.googletagmanager.com/ns.html?id=GTM-N8L3RCD"; document.getElementById('afterBody_tag_lg').src = afterBody_tag_lg_src;