title: How to get the previous viewcontroller that pushed my current view
body: <p>The home page of my app has <code>UIButtons</code>, <code>btnIncome</code> and <code>btnExpense</code>. Pressing on this buttons pushes <code>IncomeVC</code> and <code>ExpenseVC</code> respectevely,which are two <code>UIViewControllers</code> with <code>UITabBar</code> added via xib. The tabBar have 4 items. Selecting on each tab item adds same four view controllers(which contains <code>UITableViews</code>) as the subview of <code>IncomeVC</code> and <code>ExpenseVC</code>,like for eg, DailyVC,WeeklyVC,MonthlyVC,YearlyVC.(ie,for Income ,there is daily,weekly etc and same for Expense) (I have done like that because the <code>IncomeVC</code> and <code>ExpenseVC</code> have a <code>UIButton</code> and a <code>UIView</code> which is common for all tabs). </p>
  
  <p>So the problem is that, if click the <code>btnIncome</code> I have to populate those tableviews with the arrays related to Income and vice versa for Expense. How can I find from which viewController I selected the different tabs(I need to get it from the 4 Views I added as the subview of IncomeVC and ExpenseVC). Do I have to make 8 different views 4 each for Income and expense ?
  Thanx.</p>