function ajaxSendMessage()
{
    var client = new XMLHttpRequest();
    
    client.onreadystatechange = function()
    {
        if(client.readyState == 4)
        {
            if(client.status == 200)
            {
                if(client.responseText == '')
                {
                    alert('Message sent!');
                    
                    // clear the message field
                    document.getElementById('contact-form-message').value = '';
                    defaultText('contact-form-message', 'Message', false);
                }
                else
                {
                    alert(client.responseText);
                }
                
                // clear the security code field
                document.getElementById('contact-form-code').value = '';
                defaultText('contact-form-code', 'Code', false);
                
                // reload security code image
                var codeField = document.getElementById('contact-form-code-img');
                codeField.src = 'scripts/security.php?x=' + (new Date()).getTime();
            }
            else
            {
                alert("Hm... error! " + client.statusText);
            }
        }
    };
    
    var message = document.getElementById('contact-form-message').value;
    var code = document.getElementById('contact-form-code').value;
    
    var url = domain + 'scripts/message.php';
    
    var data = 'message=' + escape(message) + '&code=' + escape(code);
    
    client.open('POST', url, true);
    
    client.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    
    client.send(data);
}