diff -r 8ee8c9ea2a9f -r cd85b780f4a5 js/playscreen.js
--- a/js/playscreen.js	Thu Apr 04 17:44:59 2013 +0200
+++ b/js/playscreen.js	Wed Apr 10 15:39:28 2013 +0200
@@ -4,6 +4,20 @@
 
 var deltaT = new Date("Wed, 02 May 2012 19:00:00 +0000") / 1000 + adjust;
 
+function secsToString(seconds) {
+    var hours = Math.floor(seconds/3600),
+        minutes = Math.floor(seconds/60) % 60,
+        secs = Math.floor(seconds % 60);
+    function pad(n) {
+        var r = n.toString();
+        while (r.length < 2) {
+            r = "0" + r;
+        }
+        return r;
+    }
+    return (hours ? (hours + ":") : "") + pad(minutes) + ":" + pad(secs);
+}
+
 function solrUrl(table, params) {
     var u = "http://159.217.144.101:8050/sia-solr/" + table + "/select?" + $.param(params) + "&wt=json&json.wrf=?";
     console.log(u);
@@ -12,6 +26,42 @@
 
 function showData() {
     
+    data.chapters = [];
+    
+    data.segments.forEach(function(segment, index) {
+    	var topics = segment.topics.filter(function(t) {
+    		return t.topic !== topicPoubelle;
+    	}).map(function(t) {
+    		return t.topic
+		});
+    	var openchapters = data.chapters.filter(function(c) {
+    		return c.open;
+    	});
+    	openchapters.forEach(function(c) {
+    		var i = topics.indexOf(c.topic);
+    		if (i == -1) {
+    			c.open = false;
+    		} else {
+    			c.endMMSO = index;
+    			c.endTime = segment.end;
+    			topics.splice(i, 1);
+    		}
+    	});
+    	
+    	if (topics.length) {
+    		topics.forEach(function(t) {
+    			data.chapters.push({
+    				startMMSO: index,
+    				endMMSO: index,
+    				startTime: segment.start,
+    				endTime: segment.end,
+    				topic: t,
+    				open: true
+    			})
+    		})
+    	}
+    });
+    
 	data.topiclabels.forEach(function(v) {
 		var words = _(v.words).map(function(v, k) {
 			return {
@@ -49,20 +99,6 @@
     	})
     
     var ordertag = 0;
-
-    function secsToString(seconds) {
-        var hours = Math.floor(seconds/3600),
-            minutes = Math.floor(seconds/60) % 60,
-            secs = Math.floor(seconds % 60);
-        function pad(n) {
-            var r = n.toString();
-            while (r.length < 2) {
-                r = "0" + r;
-            }
-            return r;
-        }
-        return (hours ? (hours + ":") : "") + pad(minutes) + ":" + pad(secs);
-    }
     
     $(".duration").text(secsToString(data.duration));
         
@@ -120,10 +156,44 @@
     			return parseInt($(this).attr("data-topic-id"));
 			})
 		);
-    	for (var i = 0; i < data.segments.length; i++) {
-    		var mmso = data.segments[i];
-    		if (mmso.start >= player.currentTime && hasTopics(mmso, topics)) {
-    			player.setCurrentTime(mmso.start);
+    	for (var i = 0; i < data.chapters.length; i++) {
+    		var chap = data.chapters[i];
+    		if (chap.startTime > player.currentTime && topics.indexOf(chap.topic) !== -1) {
+    			player.setCurrentTime(chap.startTime);
+				throttledShowLocal();
+				return;
+    		}
+    	}
+    	/* If next not found, loop around ! */
+    	for (var i = 0; i < data.chapters.length; i++) {
+    		var chap = data.chapters[i];
+    		if (topics.indexOf(chap.topic) !== -1) {
+    			player.setCurrentTime(chap.startTime);
+				throttledShowLocal();
+				return;
+    		}
+    	}
+    }
+    
+    function goToPrev() {
+    	var topics = Array.prototype.slice.call(
+    		$(".topic.selected").map(function() {
+    			return parseInt($(this).attr("data-topic-id"));
+			})
+		);
+    	for (var i = data.chapters.length; i--;) {
+    		var chap = data.chapters[i];
+    		if (chap.startTime < (player.currentTime - 2) && topics.indexOf(chap.topic) !== -1) {
+    			player.setCurrentTime(chap.startTime);
+				throttledShowLocal();
+				return;
+    		}
+    	}
+    	/* If previous not found, loop around ! */
+    	for (var i = data.chapters.length; i--;) {
+    		var chap = data.chapters[i];
+    		if (topics.indexOf(chap.topic) !== -1) {
+    			player.setCurrentTime(chap.startTime);
 				throttledShowLocal();
 				return;
     		}
@@ -502,7 +572,9 @@
     		+ '<% if (show_link) { %><a href="#" data-user-id="<%- data.from_user_id %>"><% } %>'
     		+ '<img src="<%- data.profile_image_url %>" /><% if (show_link) { %></a><% } %>'
     		+ '<p><% if (show_link) { %><a href="#" data-user-id="<%- data.from_user_id %>"><% } %>'
-    		+ '@<%- data.from_user_name %>:<% if (show_link) { %></a><% } %> <%= htext %></p></li>'),
+    		+ '@<%- data.from_user_name %>:<% if (show_link) { %></a><% } %> <%= htext %></p>'
+    		+ '<% if (show_time) { %><p><%- secsToString(timestamp) %></p><% } %>'
+    		+ '</li>'),
     	callnum = 0,
     	tweetstructure = {},
     	requestedtweets = {},
@@ -563,6 +635,12 @@
 			var randtweets = data.randomtweets.filter(function(tw) {
 				return (tw.timestamp > (localpos - localduration / 2)) && (tw.timestamp < (localpos + localduration / 2))
 			});
+			if (selectedWord) {
+				var rx = new RegExp(selectedWord.replace(/(\W)/gm,'\\$1'),'im');
+				randtweets = randtweets.filter(function(tw) {
+					return rx.test(tw.data.text);
+				});
+			}
 			var mod = Math.ceil(randtweets.length / 8);
 			randtweets = randtweets.filter(function(v,k) {
 				return !(k % mod);
@@ -585,6 +663,7 @@
 		
 		tweetstoshow.forEach(function(tw) {
 			tw.show_link = true;
+			tw.show_time = false;
 		});
 		
 		tweetstoshow.sort(function(a, b) {
@@ -755,10 +834,10 @@
    	player.duration = data.duration;
    	
    	player.on("play", function() {
-   		$(".play-button").html("▐&nbsp;▌");
+   		$(".play-button").attr("title","Pause").addClass("playing");
    	});
    	player.on("pause", function() {
-   		$(".play-button").text("▶");
+   		$(".play-button").attr("title","Lecture").removeClass("playing");
    	});
    	player.on("timeupdate", function(t) {
    		playTime.text(secsToString(t));
@@ -779,10 +858,19 @@
    		} else {
    			player.pause();
    		}
+   		return false;
    	});
     
-    $(".next-button").click(goToNext);
+    $(".next-button").click(function() {
+    	goToNext();
+    	return false;
+	});
     
+    $(".prev-button").click(function() {
+    	goToPrev();
+    	return false;
+	});
+	
     $(".topics-block").on("mouseenter", ".topic", function() {
         var el = $(this);
         el.addClass("hover");
@@ -922,7 +1010,8 @@
 						weight: 0,
 						data: tweet,
 						htext: _(tweet.text).escape(),
-						show_link: false
+						show_link: false,
+						show_time: true
 					});
 				},"");
 				$(".user-tweets").show();