sheep_on = new Image;
    sheep_on.src="/graphics/header_trees.jpg";
    sheep_off = new Image;
    sheep_off.src="/graphics/header_sheep.jpg";

    zucc_on = new Image;
    zucc_on.src="/graphics/header_garlic.jpg";
    zucc_off = new Image;
    zucc_off.src="/graphics/header_zucc.jpg";

    buckets_on = new Image;
    buckets_on.src="/graphics/header_goats.jpg";
    buckets_off = new Image;
    buckets_off.src="/graphics/header_buckets.jpg";

    cows_on = new Image;
    cows_on.src="/graphics/header_logs.jpg";
    cows_off = new Image;
    cows_off.src="/graphics/header_cows.jpg";

    strawberries_on = new Image;
    strawberries_on.src="/graphics/header_grapes.jpg";
    strawberries_off = new Image;
    strawberries_off.src="/graphics/header_strawberries.jpg";


    function over_image(parm_name)
    {
    document[parm_name].src = eval(parm_name + "_on.src");
    }
    function off_image(parm_name)
    {
    document[parm_name].src = eval(parm_name + "_off.src");
    }