var url = "http://www.logosware.com/social-media/lwch/button/button.php?type=4";
		var next_start;
		var next_end;
		var minute15 = 1000 * 60 * 15;
		var button_visible = false;
		var timer_id;
		
		/**
		 * 次のイベント取得。
		 */
		function getNextEvent() {
		
			$.getJSON(url,{}, function (response) {
				var start = response.date + " " + response.startTime;
				var end = response.date + " " + response.endTime;
				
				try {
					// 時間
					start = start.replace(/-/g, "/") + ":00";
					end = end.replace(/-/g, "/") + ":00";
					
					next_start = Date.parse(start);
					next_end = Date.parse(end);
					
					// エリア表示 ==================================
					var now = new Date();
					var x = next_start - now;
					var y = next_end - now;
					
					if (x < minute15) {
						button_visible = true;
						// スレッド開始
						timer_id = startThread();
						
						$('#play a').attr("class", "viewBtn");
						$('#play a').attr("href", response.url);
						$('#lwchTopBtn').show();
						
						// 終わったときに再度取得
						setTimeout(getNextEvent, y + 600 * 1000);
					}
					else if ((next_end - now) < 0) {
						button_visible = false;
						stopThread(timer_id);
						$('#lwchTopBtn').hide();
					}
				}
				catch (ex) {
					alert(ex.message);
				}
				
			});
		}
		
		function draw(time) {
			$('#timer').html(time);		
		}
		
		function startThread() {
			var tid = setInterval(function() {
				threadMain();
			}, 1000);
			
			return tid;
		}
		
		function stopThread(timer_id) {
			clearInterval(timer_id);
		}
		
		function threadMain() {
		
			if (!button_visible) {
				return;
			}
		
			var now = new Date();
			var m, s;
			var sec = Math.floor((next_start - now) / 1000);

			s = sec % 60;
			m = Math.floor(sec / 60);
			m = m % 60;
			
			// ================================
			
			if (s <= 0) {
				draw("00:00");
				
				$('#play a').attr("class", "nowOnAir");
				stopThread(timer_id);
			}
			else {
				if (s < 10) {
					s = "0" + s;
				}
				if (m < 10) {
					m = "&nbsp;" + m;
				}
				
				draw(m + ":" + s);
			}
		}
		
		function lwch() {
			getNextEvent();
		}