isValid = False
        while isValid != True:
            gameStr = raw_input ("Choose a space to place the card: ")
            #the below makes sure that the input is a digit
            if gameStr.isdigit() != True:
                print "Not valid input. Please input a digit."
                isValid = False
                continue
            gameNum = int(gameStr)
            #the below makes sure input is between 1 and 20
            if gameNum <= 0 or gameNum > 20:
                print "Not a valid space.  Please choose again."
                isValid = False
                continue
            #the below makes sure the user does not place a second card in any slot
            if cardList[gameNum].get_val() != 0:
                print "Space already taken.  Please select a different space."
                isValid = False
                continue
            #if we made it here, it's good
            isValid = True