We will use Python to implement a program where each screen is a 
separate module. So each screen could be designed by a different 
person on the project. Each module provides a separate namespace:

#!/usr/bin/python

import One, Data, Two, Store

print "Content-type: text/html\n\n"; 

if Data.source == "One": 
  if Data.roll: 
    Two.show()
  else: 
    Store.show()
else: 
  One.show()

#---------------------------------------------------------------

def show():
  print """
<form>
This is screen One. <p> 
<input type="submit" name="roll"  value="Roll Again!"> 
<input type="submit" name="store" value="Store Combination"> 
<input type="hidden" name="source" value="One"> 
</form> 
"""

#---------------------------------------------------------------

def show():
  print """
<form>
This is screen Two. <p> 
<input type="submit" name="roll"  value="Roll Again!"> 
<input type="submit" name="store" value="Store Combination"> 
<input type="hidden" name="source" value="Two"> 
</form> 
"""

#---------------------------------------------------------------

def show():
  print """
<form>
Store your combination as: <select name=choice>
<option> Ones
<option> Twos
<option> Threes
<option> Full House
<option> Yahtzee
<option> Chance
</select> <p> 
Click <input type=submit value="Roll Dice"> to start new game. 
<input type="hidden" name="source" value="Store"> 
</form> 
"""

#---------------------------------------------------------------

import cgi

q = cgi.FieldStorage()

(source, roll) = ("", "")
if (q.has_key("source")): source = q["source"].value
if (q.has_key("roll")):   roll   = q["roll"].value