title: Trouble closing loops or creating a prompt to progress
body: <p>I am struggling with the "while" command and loops in general. I am missing a stopping point but I don't know how to create one. I am trying to create a program to simulate a primitive stock option choice but it just cycles trough the first 2 loops without a stopping point. Any help would be appreciated.</p>
  
  <pre><code>selection = " "
  while selection not in ("r","R","t","T"):
  print("This program can operate in random mode (fluctuations will randomly occur) or it      can operate in test mode (fluctuations are fixed).")
  print("(r)andom mode")
  print("(t)est mode")
  selection = input("Mode of operation:")
  if selection not in ("r","R","t","T"):
      print("\nPlease select 'r' or 't' for mode selection\n")
  elif (selection == "r"):
      print("Random mode enabled")
      n = random.randrange(1,101)
      selection = " "
      while selection not in ("1","2","3"):
          print("\tInvestment options:")
          print("(1)Fly-By-Night Investments (FBN): high risk, high potential returns")
          print("(2)Blue Chips INC. (BCI): moderate risk, good potential yearly returns")
          print("(3)Slow-And-Steady-Corp. (SNS), mature industry stock: no risk but low returns")
          selection = input("Please enter your investment option 1, 2, or 3:")
          if selection not in ("1","2","3"):
              print("\nPlease enter an investment option from the menu using 1, 2, or 3 as valid selections:\n")
  </code></pre>
  
  <p>The random and test mode come later in the program but I wanted to show the loops where I dont have a stopping point anywhere. It just cycles through the two.</p>