public ActionResult ManageBudgetCategory(ManageBudgetCategoryViewModel budgetDetailsViewModel, string categoryName)
        {
            if (ModelState.IsValid)
            {
                using (budgetRepository)
                {
                    if (budgetRepository.AddBudgetCategory(categoryName, SessionUserId))
                    {
                        return(RedirectToAction("ManageBudgetCategory"));
                    }
                    else
                    {
                        ModelState.AddModelError("", "Error in creating budget category. Try again!");
                    }
                }
            }
            else
            {
                ModelState.AddModelError("", "The submitted form contain errors. Please correct them and submit again!");
            }

            budgetDetailsViewModel.AddCategory = new BudgetCategory
            {
                CategoryName = categoryName
            };
            return(View("ManageBudgetCategory", budgetDetailsViewModel));
        }