function ser_on(){
	document.getElementById("ser_child").style.visibility='visible';
}
function ser_off(){
	document.getElementById("ser_child").style.visibility='hidden';
}

function deco_on(){
	document.getElementById("deco_child").style.visibility='visible';
}
function deco_off(){
	document.getElementById("deco_child").style.visibility='hidden';
}
function com_on(){
	document.getElementById("com_child").style.visibility='visible';
}
function com_off(){
	document.getElementById("com_child").style.visibility='hidden';
}