function focus() {
	if (document.palautelomake) {
		if (document.palautelomake.palaute) {
			document.palautelomake.palaute.focus();
		}
	}
}

function showLayer(whichLayer) {
	if (document.getElementById) { // standardin mukainen tapa
		var divstyle = document.getElementById(whichLayer).style;
		divstyle.display = "";
	} else if (document.all) { // wanhat iexplorerit
		var divstyle = document.all[whichLayer].style;
		divstyle.display = "";
	} else if (document.layers) { // netscape navigator 4
		var divstyle = document.layers[whichLayer].style;
		divstyle.display = "";
	}
}

function hideLayer(whichLayer) {
	if (document.getElementById) { // standardin mukainen tapa
		var divstyle = document.getElementById(whichLayer).style;
		divstyle.display = "none";
	} else if (document.all) { // wanhat iexplorerit
		var divstyle = document.all[whichLayer].style;
		divstyle.display = "none";
	} else if (document.layers) { // netscape navigator 4
		var divstyle = document.layers[whichLayer].style;
		divstyle.display = "none";
	}
}

function validate(form) {
	hideLayer('palaute_virhe');
	hideLayer('nimi_virhe');
	hideLayer('yhteystiedot_virhe');

	if (form.palaute.value == "") {
		showLayer('palaute_virhe');
		form.palaute.focus();
		return false;
	}
	if (!form.nimeton.checked) {
		if (form.nimi.value == "") {
			showLayer('nimi_virhe');
			form.nimi.focus();
			return false;
		}
		if (form.yhteydenotto.checked && form.yhteystiedot.value == "") {
			showLayer('yhteystiedot_virhe');
			form.yhteystiedot.focus();
			return false;
		}
	}
	return true;
}

function change() {
	var form = document.forms.palautelomake;
	form.nimi.disabled = form.nimeton.checked;
	form.yhteystiedot.disabled = form.nimeton.checked;	
}