--- a/static/js/main.js	Tue Mar 12 02:23:34 2013 +0900
+++ b/static/js/main.js	Tue Mar 12 13:56:00 2013 +0900
@@ -1,59 +1,72 @@
 var ws = new WebSocket('ws://' + location.host + '/ws');
+var initiator;
 var pc;
 
 
 function call() {
     $('#btn-call').addClass('btn-active');
-    init(true);
+    initiator = true;
+    init();
 }
 
 
 function receive() {
     $('#btn-receive').addClass('btn-active');
-    init(false);
+    initiator = false;
+    init();
 }
 
 
-function init(initiator) {
+function init() {
     var constraints = {
         audio: $('#audio').prop('checked'),
         video: $('#video').prop('checked')
     };
     
-    getUserMedia(constraints, function(stream) {
-        pc = new RTCPeerConnection(null);
-        
+    if (constraints.audio || constraints.video) {
+        getUserMedia(constraints, connect, fail);
+    } else {
+        connect();
+    }
+}
+
+
+function connect(stream) {
+    pc = new RTCPeerConnection(null);
+    
+    if (stream) {
         pc.addStream(stream);
-        $('#local').prop('src', URL.createObjectURL(stream));
-        pc.onaddstream = function(event) {
-            $('#remote').prop('src', URL.createObjectURL(event.stream));
-            logStreaming(true);
-        };
-        pc.onicecandidate = function(event) {
-            if (event.candidate) {
-                ws.send(JSON.stringify(event.candidate));
+        $('#local').attachStream(stream);
+    }
+    
+    pc.onaddstream = function(event) {
+        $('#remote').attachStream(event.stream);
+        logStreaming(true);
+    };
+    pc.onicecandidate = function(event) {
+        if (event.candidate) {
+            ws.send(JSON.stringify(event.candidate));
+        }
+    };
+    ws.onmessage = function (event) {
+        var signal = JSON.parse(event.data);
+        if (signal.sdp) {
+            if (initiator) {
+                receiveAnswer(signal);
+            } else {
+                receiveOffer(signal);
             }
-        };
-        ws.onmessage = function (event) {
-            var signal = JSON.parse(event.data);
-            if (signal.sdp) {
-                if (initiator) {
-                    receiveAnswer(signal);
-                } else {
-                    receiveOffer(signal);
-                }
-            } else if (signal.candidate) {
-                pc.addIceCandidate(new RTCIceCandidate(signal));
-            }
-        };
-        
-        if (initiator) {
-            createOffer();
-        } else {
-            log('waiting for offer...');
+        } else if (signal.candidate) {
+            pc.addIceCandidate(new RTCIceCandidate(signal));
         }
-        logStreaming(false);
-    }, fail);
+    };
+    
+    if (initiator) {
+        createOffer();
+    } else {
+        log('waiting for offer...');
+    }
+    logStreaming(false);
 }
 
 
@@ -105,3 +118,11 @@
     $('#status').text(Array.prototype.join.call(arguments, ' '));
     console.error.apply(console, arguments);
 }
+
+
+jQuery.fn.attachStream = function(stream) {
+    this.each(function() {
+        this.src = URL.createObjectURL(stream);
+        this.play();
+    });
+};