--- loncom/interface/loncommon.pm	2011/08/03 18:25:11	1.1016
+++ loncom/interface/loncommon.pm	2011/08/15 05:16:30	1.1017
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # a pile of common routines
 #
-# $Id: loncommon.pm,v 1.1016 2011/08/03 18:25:11 raeburn Exp $
+# $Id: loncommon.pm,v 1.1017 2011/08/15 05:16:30 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -630,6 +630,51 @@ function getDomainFromSelectbox(formname
 
 ENDJS
 
+}
+
+sub javascript_array_indexof {
+    return <<ENDJS; 
+<script type="text/javascript" language="JavaScript">
+// <![CDATA[
+
+if (!Array.prototype.indexOf) {
+    Array.prototype.indexOf = function (searchElement /*, fromIndex */ ) {
+        "use strict";
+        if (this === void 0 || this === null) {
+            throw new TypeError();
+        }
+        var t = Object(this);
+        var len = t.length >>> 0;
+        if (len === 0) {
+            return -1;
+        }
+        var n = 0;
+        if (arguments.length > 0) {
+            n = Number(arguments[1]);
+            if (n !== n) { // shortcut for verifying if it's NaN
+                n = 0;
+            } else if (n !== 0 && n !== (1 / 0) && n !== -(1 / 0)) {
+                n = (n > 0 || -1) * Math.floor(Math.abs(n));
+            }
+        }
+        if (n >= len) {
+            return -1;
+        }
+        var k = n >= 0 ? n : Math.max(len - Math.abs(n), 0);
+        for (; k < len; k++) {
+            if (k in t && t[k] === searchElement) {
+                return k;
+            }
+        }
+        return -1;
+    }
+}
+
+// ]]>
+</script>
+
+ENDJS
+
 }
 
 sub userbrowser_javascript {