window.setInterval("tippRoller('startbild')", 5000);

var visibleTipp = 1;

function tippRoller(prefix) {
    var node = $(prefix + visibleTipp);
    var nextNode = $(prefix + (++visibleTipp));
    if(visibleTipp==4) {
        visibleTipp=1;
        nextNode = $(prefix + visibleTipp);
    }
    if (node) node.hide();
    new Effect.Appear(nextNode, {queue:'end'});
}