function fn_show_layer1(flag){
	if(flag=='show')
		submenu_layer1.style.visibility='visible';
	else if(flag=='hide')
		submenu_layer1.style.visibility='hidden';
}
function fn_show_layer2(flag){
	if(flag=='show')
		submenu_layer2.style.visibility='visible';
	else if(flag=='hide')
		submenu_layer2.style.visibility='hidden';
}
function fn_show_layer3(flag){
	if(flag=='show')
		submenu_layer3.style.visibility='visible';
	else if(flag=='hide')
		submenu_layer3.style.visibility='hidden';
}
function fn_show_layer4(flag){
	if(flag=='show')
		submenu_layer4.style.visibility='visible';
	else if(flag=='hide')
		submenu_layer4.style.visibility='hidden';
}