function backToTop() {
var x1 = x2 = x3 = 0;
var y1 = y2 = y3 = 0;
if (document.documentElement) {
x1 = document.documentElement.scrollLeft || 0;
y1 = document.documentElement.scrollTop || 0;
}
if (document.body) {
x2 = document.body.scrollLeft || 0;
y2 = document.body.scrollTop || 0;
}
x3 = window.scrollX || 0;
y3 = window.scrollY || 0;
var x = Math.max(x1, Math.max(x2, x3));
var y = Math.max(y1, Math.max(y2, y3));
window.scrollTo(Math.floor(x / 2), Math.floor(y / 2));
if (x > 0 || y > 0) {
window.setTimeout("backToTop()", 25);
}
}

function layer_show_hide(){
	var item1 = $('layer'); 
	var item2 = $('text01');
	var item3 = $('text02');
	Element.toggle(item1); 
	Element.toggle(item2); 
	Element.toggle(item3); 
}