layered keyboard commands

[Sean Farrow]

Hi:
I'm currently scripting an application and I would like to use a concept of 
layered keys.
If I press one key, I'd then like the keyboard to freeze and only allow certain 
other keys through within a specific time period (5 seconds I'm thinking). If a 
key is press within this time the function that key is tied to is executed, if 
not the keyboard is unfrozen after the time has expired.
If there an easy way of doing this in scripting?
Regards
Sean.