diff --git a/js/import.js b/js/import.js
index f1ef6ebcb..557ca61e4 100644
--- a/js/import.js
+++ b/js/import.js
@@ -28,10 +28,10 @@ function changePluginOpts() {
  * in the plugin dropdown list according to the format of the selected file
  */
 function matchFile(fname) {
-    fname_array = fname.toLowerCase().split(".");
-    len = fname_array.length;
+    var fname_array = fname.toLowerCase().split(".");
+    var len = fname_array.length;
     if(len != 0) {
-        extension = fname_array[len - 1];
+        var extension = fname_array[len - 1];
         if (extension == "gz" || extension == "bz2" || extension == "zip") {
             len--;
         }