function validate_comment_params() {

	var valid_comment_name = 0;
	var valid_comment_email = 0;
	var valid_comment_text = 0;
	
	var comment_email = document.getElementById('email').value;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if (document.getElementById('name').value != '') { valid_comment_name = 1; }
	if (filter.test(comment_email)) { valid_comment_email = 1; }
	if (document.getElementById('comment').value != '') { valid_comment_text = 1; }

	if (valid_comment_name == 1 && valid_comment_email == 1 && valid_comment_text == 1) {
		return true; 
	} else {

		var error_message = '';
	
		if (valid_comment_name == 0)  { error_message += '- Your name.\n';  }
		if (valid_comment_email == 0) { error_message += '- Your email address.\n'; }
		if (valid_comment_text == 0) { error_message += '- Your comment.\n'; }
		
		alert("Please complete the following fields:\n\n" + error_message);
		return false;
	}
}

function validate_email_request_params() {

	var valid_recipient_email = 0;
	var valid_sender_email = 0;
	
	var recipient_email = document.getElementById('recipient_email').value;
	var sender_email = document.getElementById('sender_email').value;
	
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if (filter.test(recipient_email)) { valid_recipient_email = 1; }
	if (filter.test(sender_email)) { valid_sender_email = 1; }
	
	if (valid_sender_email == 1 && valid_recipient_email == 1) {
		return true;
	} else {

		var error_message = '';
	
		if (valid_recipient_email == 0) { error_message += '- The recipient\'s email address.\n'; }
		if (valid_sender_email == 0) { error_message += '- Your email address.\n'; }
		
		alert("Please complete the following fields:\n\n" + error_message);
		return false;
	}
}

function validate_contact_request_params() {

	var valid_contact_name = 0;
	var valid_contact_email = 0;
	var valid_contact_subject = 0;
	var valid_contact_message = 0;
	
	var contact_email = document.getElementById('contact_email').value;
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if (document.getElementById('contact_name').value != '') { valid_contact_name = 1; }
	if (filter.test(contact_email)) { valid_contact_email = 1; }
	if (document.getElementById('contact_subject').value != '') { valid_contact_subject = 1; }
	if (document.getElementById('contact_message').value != '') { valid_contact_message = 1; }

	if (valid_contact_name == 1 && valid_contact_email == 1 && valid_contact_subject == 1 && valid_contact_message == 1) { 
		return true; 
	} else {

		var error_message = '';
	
		if (valid_contact_name == 0)  { error_message += '- Your name.\n';  }
		if (valid_contact_email == 0) { error_message += '- Your email address.\n'; }
		if (valid_contact_subject == 0) { error_message += '- The subject.\n'; }
		if (valid_contact_message == 0) { error_message += '- The message.\n'; }
		
		alert("Please complete the following fields:\n\n" + error_message);
		return false;
	}
}