void CreateQuestionBank(string bankname)
    {
        UploadMessage.GetComponent <Text>().text = "Uploading...";
        Debug.Log("Start to upload question bank " + bankname);
        ResultPanel.SetActive(true);
        // yield return fc.CreateQuestionBank(holder.BankName, holder.GetQuestionBank());

        fc.CreateQuestionBank(bankname, holder.GetQuestionBank()).Then(result =>
        {
            if (result)
            {
                // Show uploaded message and return to login page
                UploadMessage.GetComponent <Text>().text = "Succeed to Upload Question bank [" + bankname + "]. Now return to Login Page.";
            }
            else
            {
                UploadMessage.GetComponent <Text>().text = "Failed to Upload Question bank [" + bankname + "]. Please Try again later";
            }


            Debug.Log("Wait 3 seconds to login page");
            return(Timer.WaitFor(5f));
        }).Then(() =>
        {
            Debug.Log("Load scene Login");
            SceneManager.LoadScene("Login");
        });
    }