diff --git a/static/js/ace2_common.js b/static/js/ace2_common.js
index 1e5c415c7..d08c521a1 100644
--- a/static/js/ace2_common.js
+++ b/static/js/ace2_common.js
@@ -95,7 +95,8 @@ var browser = {
   opera: /opera/.test(userAgent),
   msie: /msie/.test(userAgent) && !/opera/.test(userAgent),
   mozilla: /mozilla/.test(userAgent) && !/(compatible|webkit)/.test(userAgent),
-  windows: /windows/.test(userAgent) // dgreensp
+  windows: /windows/.test(userAgent)
+  mobile: /mobile/.test(userAgent) || /android/.test(userAgent);
 };
 
 
diff --git a/static/js/ace2_inner.js b/static/js/ace2_inner.js
index 2b2d05f2b..5ca25c7ff 100644
--- a/static/js/ace2_inner.js
+++ b/static/js/ace2_inner.js
@@ -86,11 +86,6 @@ function OUTER(gscope)
   var hasLineNumbers = true;
   var isStyled = true;
   
-  // check for mobile os presence
-  var ua = navigator.userAgent.toLowerCase();
-  var isAndroid = ua.indexOf("android") > -1;
-  var isMobileSafari = ua.indexOf("mobile") > -1;
-
   // space around the innermost iframe element
   var iframePadLeft = MIN_LINEDIV_WIDTH + LINE_NUMBER_PADDING_RIGHT + EDIT_BODY_PADDING_LEFT;
   var iframePadTop = EDIT_BODY_PADDING_TOP;
@@ -1111,7 +1106,7 @@ function OUTER(gscope)
     {
       hasLineNumbers = !! value;
       // disable line numbers on mobile devices
-      if(isAndroid || isMobileSafari) hasLineNumbers = false;
+      if (mobile.browser) hasLineNumbers = false;
       setClassPresence(sideDiv, "sidedivhidden", !hasLineNumbers);
       fixView();
     }
diff --git a/static/js/chat.js b/static/js/chat.js
index 4dade69f3..5cae5919a 100644
--- a/static/js/chat.js
+++ b/static/js/chat.js
@@ -22,9 +22,6 @@
 
 var chat = (function()
 {
-  var ua = navigator.userAgent.toLowerCase();
-  var isAndroid = ua.indexOf("android") > -1;
-  var isMobileSafari = ua.indexOf("mobile") > -1;
   var bottomMargin = "0px";
   var sDuration = 500;
   var hDuration = 750;
@@ -57,7 +54,7 @@ var chat = (function()
           {
             $("#focusprotector").hide();
             
-            if(isAndroid || isMobileSafari)
+            if(browser.mobile)
               bottommargin = "32px";
             
             $("#chatbox").css({right: "20px", bottom: bottomMargin, left: "", top: ""});