diff --git a/build/css/ox.ui.css b/build/css/ox.ui.css
index 72bccefe..5551b510 100644
--- a/build/css/ox.ui.css
+++ b/build/css/ox.ui.css
@@ -118,6 +118,9 @@ Dialog
 .OxDialog > .OxButtonsBar > .OxButton.OxLeft {
     float: left;
 }
+.OxDialog > .OxButtonsBar > .OxButton.OxLeft:first-child {
+    margin-left: 16px;
+}
 .OxDialog > .OxButtonsBar > .OxButton.OxRight {
     float: right;
 }
diff --git a/build/js/ox.ui.js b/build/js/ox.ui.js
index b57e4d46..9b305f82 100644
--- a/build/js/ox.ui.js
+++ b/build/js/ox.ui.js
@@ -1269,6 +1269,7 @@ requires
             .addClass("OxTitleBar")
             //.html(self.options.title)
             .mousedown(drag)
+            .dblclick(center)
             .appendTo(that);
         that.$title = new Ox.Element()
             .addClass("OxTitle")
@@ -1310,6 +1311,16 @@ requires
         that.$layer = new Ox.Element()
             .addClass("OxLayer");
 
+        function center() {
+            that.css({
+                left: 0,
+                top: parseInt(-$document.height() / 10) + "px", // fixme: duplicated
+                right: 0,
+                bottom: 0,
+                margin: "auto"
+            });
+        }
+
         function drag(event) {
             var documentWidth = $document.width(),
                 documentHeight = $document.height(),
diff --git a/demos/test/index.html b/demos/test/index.html
index f548c0cb..51d7225f 100644
--- a/demos/test/index.html
+++ b/demos/test/index.html
@@ -195,10 +195,14 @@
 
                 var loginDialog = new Ox.Dialog({
                     buttons: [
-                        { value: "Register", click: function() { loginDialog.close(); } },
-                        { value: "Reset Password", click: function() { loginDialog.close(); } },
-                        { value: "Cancel", click: function() { loginDialog.close(); } },
-                        { value: "Login", click: function() { loginDialog.close(); } }
+                        [
+                            { value: "Register", click: function() { loginDialog.close(); } },
+                            { value: "Reset Password", click: function() { loginDialog.close(); } }
+                        ],
+                        [
+                            { value: "Cancel", click: function() { loginDialog.close(); } },
+                            { value: "Login", click: function() { loginDialog.close(); } }
+                        ]
                     ],
                     title: "Login"
                 });