// JavaScript Document
function btn_click(n) {
	for ( var i = 1; i <= max_num ; i++ ) {
		document.getElementById("a"+i).style.display = "none";
	}
	document.getElementById("a"+n).style.display = "block";
	document.getElementById(first_position).style.backgroundPosition ="5px 0.5em";
	document.getElementById(first_position).style.backgroundImage ="url(./img/list_icon.gif)";
	first_position = "q"+n;
	document.getElementById("q"+n).style.backgroundPosition ="2px 0.4em";
	document.getElementById("q"+n).style.backgroundImage ="url(./img/list_icon_now.gif)";
}