function writeHeader(header_character)
{
    today = new Date();
    hours = today.getHours();

    switch (hours)
    {
        case 5:
        case 6:
        case 7:
            var header_image = 1;
            break;
            
        case 8:
        case 9:
            var header_image = 2;
            break;

        case 10:
        case 11:
            var header_image = 3;
            break;

        case 12:
        case 13:
        case 14:
        case 15:
            var header_image = 4;
            break;

        case 16:
        case 17:
        case 18:
            var header_image = 5;
            break;

        case 19:
        case 20:
            var header_image = 6;
            break;

        case 21:
        case 22:
        case 23:
        case 0:
        case 1:
        case 2:
            var header_image = 7;
            break;

        case 3:
        case 4:
            var header_image = 8;
            break;
    }
    
    //  Add the required classes to the header block
    var site_header = document.getElementById('site_header');
    site_header.style.background = 'url(http://images.shaunthesheep.com/head/' + header_character + '/' + header_image + '.jpg) no-repeat';
}