/// <summary>
/// Clears all data from the DataLists and SubCategory Lists.
/// </summary>
private void ClearData()
{
DataViewModel.ClearData();
SubCategoryViewModel.ClearData();
Income.ClearData();
Expense.ClearData();
WindowTitle = "Budget Planner";
BudgetFileName = String.Empty;
MainFileDirectory = String.Empty;
CategoryDirectory = String.Empty;
}