function validanews(form)
{
  if(form.email_news.value.length < 1)
  {
    alert("Informe o E-mail");
    form.email_news.focus();
    return false;
  }
  if((form.email_news.value.indexOf("@")=='-1') || (form.email_news.value.indexOf(".")=='-1'))
  {
    alert("E-mail incorreto");
    form.email_news.focus();
    return false;
  }
  return true;
}