String.prototype.trim = function() {
	return this.replace(/^\s+|\s+$/g,"");
}

function validateRequired(field,alerttxt) {
	with (field) {
		if (value == null || value.trim() == "") {
			alert(alerttxt);
			return false;
		}
		else {
			return true;
		}
	}
}

function validateEmail(field,alerttxt) {
	with (field) {
		apos=value.indexOf("@")
		dotpos=value.lastIndexOf(".")
		if (apos<1||dotpos-apos<2) {
		  alert(alerttxt);
		  return false;
		}
		else {
			return true;
		}
	}
}	

function cleanNewsletterArea() {
	var myForm = document.forms['my_newsletter'];
	var fEmail = myForm.nl_email;

	if (fEmail.value = 'your email here'){
		fEmail.value = '';
	}
}

function validateNewsletter() {
	var myForm = document.forms['my_newsletter'];
	var fEmail = myForm.nl_email;

	// validate name
    if (validateRequired(fEmail,"Please write your email address!") == false) {
	    fEmail.focus();
	    return false;
    }

	// email validation
	if (validateEmail(fEmail,"The email address is invalid!") == false) {
		fEmail.focus();
		return false;
	}

	return true;
}
	
function subscribeNL(){
	if (!validateNewsletter()){
		return;
	}

	$.ajax({
		type: "POST",
		url: "process/subscribe_newsletter.php",
		data: "this_email=" + document.forms['my_newsletter'].nl_email.value,
		success: alert('Thank you for your subscription!')
	});	
}