function nuevo_captcha(url) {

	var src = $("div#captcha_img img").attr('src');
	var lastChar = src.substring(src.length-1);
	if(lastChar == "2"){
		img = url + 'contactes/captcha';
	} else {
		img = url + 'contactes/captcha2';
	}

	$("div#captcha_img img").attr('src',img);

}