function isEmail(elm) {
  if(elm.value.indexOf("@") != "-1" &&
	   elm.value.indexOf(".") != "-1") {
		   return true;
	}
	else {
	  return false;
	}
}


function isFilled(elm) {
  if(elm.value == "" || elm.value == null) {
	  return false;
	}
	else {
	  return true;
	}
}

function isReady(form) {
  if(isEmail(form.email) == false) {
	  alert("Please enter a valid email address.");
		form.email.focus();
		return false;
	}
	
  if(isFilled(form.firstname) == false) {
	  alert("Please enter your first name.");
		form.firstname.focus();
		return false;
	}
	
	if(isFilled(form.lastname) ==  false) {
	  alert("Please enter your last name.");
		form.lastname.focus();
		return false;
	}
	
	return true;
}