diff --git a/program/js/common.js b/program/js/common.js
index 2abc594f9..088613d11 100644
--- a/program/js/common.js
+++ b/program/js/common.js
@@ -610,6 +610,18 @@ if (!String.prototype.startsWith) {
   };
 }
 
+if (!String.prototype.endsWith) {
+  String.prototype.endsWith = function(searchString, position) {
+    var subjectString = this.toString();
+    if (typeof position !== 'number' || !isFinite(position) || Math.floor(position) !== position || position > subjectString.length) {
+      position = subjectString.length;
+    }
+    position -= searchString.length;
+    var lastIndex = subjectString.lastIndexOf(searchString, position);
+    return lastIndex !== -1 && lastIndex === position;
+  };
+}
+
 // array utility function
 jQuery.last = function(arr) {
   return arr && arr.length ? arr[arr.length-1] : undefined;