function handleFocus(e, starting_text)
{
    if (starting_text == e.value)
    {
        e.value = '';
    }
}

function handleBlur(e, starting_text)
{
    if ('' == e.value)
    {
        e.value = starting_text;
    }
}

function hideSubscribeBlock()
{
    var e = document.getElementById('subscribe');
    var height = e.offsetHeight;
    if (0 < height)
    {
        e.style.height = (height - 1);
        setTimeout('hideSubscribeBlock()', 15);
    }
}

function subscribe()
{
    var emailVerification = /[a-zA-Z0-9._%-]+@[a-zA-Z0-9._%-]+\.[a-zA-Z]/;
    var subscriberName = document.getElementById('subscriber_name');
    var subscriberEmail = document.getElementById('subscriber_email');
    var subscribeButton = document.getElementById('subscribe_button');
    
    subscribeButton.disabled = true;
    
    if (('' == subscriberEmail.value) || !emailVerification.exec(subscriberEmail.value))
    {
        window.alert('Please enter a valid email.');
    }
    else
    {
        var oXMLHttpRequest = new XMLHttpRequest;
        oXMLHttpRequest.open("GET", "subscribe.php?name="+subscriberName.value+"&email="+subscriberEmail.value, false);
        oXMLHttpRequest.onreadystatechange = function()
        {
            if (this.readyState == XMLHttpRequest.DONE)
            {
                var e = document.getElementById("subscribe");
                e.innerHTML = oXMLHttpRequest.responseText;
                // setTimeout("hideSubscribeBlock();", 1500);
            }
        }
        oXMLHttpRequest.send(null);
    }

    subscribeButton.disabled = false;
}