diff --git a/IPython/html/tests/casperjs/test_cases/inject_js.js b/IPython/html/tests/casperjs/test_cases/inject_js.js
index 805ab83..4f72a36 100644
--- a/IPython/html/tests/casperjs/test_cases/inject_js.js
+++ b/IPython/html/tests/casperjs/test_cases/inject_js.js
@@ -12,9 +12,9 @@ casper.notebook_test(function () {
     
     this.evaluate(function () {
         var cell = IPython.notebook.get_cell(0);
-        var json = cell.toJSON()
-        json.prompt_number = "<script> alert('hello from input prompts !')</script>"
-        cell.fromJSON(j)
+        var json = cell.toJSON();
+        json.prompt_number = "<script> alert('hello from input prompts !')</script>";
+        cell.fromJSON(json);
     });
 
     this.then(function () {