function showCredits() {
	hideElem("film_info");
	showElem("film_credits");
	hideElem("film_students");
	var elem = document.getElementById("sublink_2");
	elem.className = "sublink_2_on";
	var elem = document.getElementById("sublink_1");
	elem.className = "sublink_1_off";
	var elem = document.getElementById("sublink_3");
	elem.className = "sublink_3_off";
}

function showInfo() {
	hideElem("film_credits");
	showElem("film_info");
	hideElem("film_students");
	var elem = document.getElementById("sublink_1");
	elem.className = "sublink_1_on";
	var elem = document.getElementById("sublink_2");
	elem.className = "sublink_2_off";
	var elem = document.getElementById("sublink_3");
	elem.className = "sublink_3_off";
}

function showStudents() {
	hideElem("film_credits");
	hideElem("film_info");
	showElem("film_students");
	var elem = document.getElementById("sublink_1");
	elem.className = "sublink_1_off";
	var elem = document.getElementById("sublink_2");
	elem.className = "sublink_2_off";
	var elem = document.getElementById("sublink_3");
	elem.className = "sublink_3_on";
}

function showElem(elemId) {
	var elem = document.getElementById(elemId);
	elem.style.display = "block";
}

function hideElem(elemId) {
	var elem = document.getElementById(elemId);
	elem.style.display = "none";
}