function chVisibility(id){
	if(document.getElementById(id).style.display == "none"){
		document.getElementById(id).style.display = "block";
		document.getElementById("inc_" + id).style.display = "block";
		document.getElementById("dec_" + id).style.display = "block";
	} else {
		document.getElementById(id).style.display = "none";
		document.getElementById("inc_" + id).style.display = "none";
		document.getElementById("dec_" + id).style.display = "none";
	}
}