var mTimer;
var frequency = 100;
var increment = .005;
var init_opacity = 0.1;
var max_opacity = 1;
var cur_level;

function say_thanks() {
    var element = document.getElementById('thanks_message');
    element.style.display = 'block';
    return false;
}

    function ok() {
        var form = document.getElementById('subscribe');
        form.submit();
        return true;
    }

    Event.observe(window, 'load', function() {
        init_increase_opacity('primary_image', init_opacity, max_opacity);
    });

    function init_increase_opacity (id, init_value, limit) {
        var element = $(id);
        if ( !element ) {
            return;
        }
        element.style.opacity = init_value;
        cur_level = init_value;
        mTimer = window.setInterval("increase_opacity('" + id + "'," + limit + ");",frequency);
        
    }

    function increase_opacity (id, limit) {
        var element = $(id);
        if ( !element ) {
            return;
        }
        if ( cur_level >= limit )
            window.clearInterval(mTimer);
        else {
            cur_level += increment;
            element.style.opacity = cur_level;
            element.style.filter = "alpha(opacity=" + (cur_level * 100) + ")";
        }
    }