function clearField(f) {
	if (f.value == 'email@domain.com') {
		f.value = '';
	}
}

function unClear(f) {
	if (f.value == '') {
		f.value = 'email@domain.com';
	}
}

function newsletterValid() {
	email = document.getElementById('newsletteremail').value;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if ((email == 'email@domain.com') || (email == '') || !(filter.test(email))) {
		alert ("Please enter a valid email address.");
		return false;
	}		
}