Fixed #12748 - Use charAt instead of array-like access to format stri…

…ng to please IE. Thanks, yedpodtrzitko.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12397 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/media/js/core.js

@@ -174,12 +174,12 @@ Date.prototype.strftime = function(format) {
     };
     var result = '', i = 0;
     while (i < format.length) {
-        if (format[i] === '%') {
-            result = result + fields[format[i + 1]];
+        if (format.charAt(i) === '%') {
+            result = result + fields[format.charAt(i + 1)];
             ++i;
         }
         else {
-            result = result + format[i];
+            result = result + format.charAt(i);
         }
         ++i;
     }