function showDinner() {
document.getElementById('specials').style.visibility = "hidden";
document.getElementById('lunch').style.visibility = "hidden";
document.getElementById('dinner').style.visibility = "visible";
}

function showSpecials() {
document.getElementById('specials').style.visibility = "visible";
document.getElementById('lunch').style.visibility = "hidden";
document.getElementById('dinner').style.visibility = "hidden";
}

function showLunch() {
document.getElementById('specials').style.visibility = "hidden";
document.getElementById('lunch').style.visibility = "visible";
document.getElementById('dinner').style.visibility = "hidden";
}