function selectHide(){
	selects = document.getElementsByTagName("select");
	for (i = 0; i != selects.length; i++) {
		selects[i].style.visibility = "hidden";
	}
	}
	function selectShow(){
	selects = document.getElementsByTagName("select");
	for (i = 0; i != selects.length; i++) {
		selects[i].style.visibility = "visible";
	}
	}