// PRELOADING IMAGES
if (document.images) {
 img_on =new Image();  img_on.src ="/images/menu-btnblink.gif";
 img_off=new Image();  img_off.src="/images/menu-btn.gif";
}

function handleOver(id) {
 if (document.images) document['btn-' + id].src=img_on.src;
}

function handleOut(id) {
 if (document.images) document['btn-' + id].src=img_off.src;
}

var reEmail = /^.+\@.+\..+$/
var defaultEmptyOK = false
function isEmpty(s)
{ return ((s == null) || (s.length == 0))
}

function isEmail (s)
{ if (isEmpty(s))
    if (isEmail.arguments.length == 1) return defaultEmptyOK;
    else return (isEmail.arguments[1] == true);
  else
  { return reEmail.test(s)
  }
}

function validasinewsletter(form)
{
  if (!isEmail(form.emailnews.value))
  { alert("Email harus valid (contoh: nama@namaperusahaan.com)");
     form.emailnews.focus();
     return false;
  }
  return true;
}