Facebook Page auto responder BOT

I need to create a autoresponder for facebook pages, this autoresponder "bot" answer a mathematical problem, for example: 1) The user open the facebook page 2) The user send a message that says: Hi 3) The "bot" answer "hi, how are you today + 'name'" 4) The user says: "What is the result of: 5+5 5) The bot says "the result is 10" The script is basically a Bot for Facebook fan pages,In order to create custom answers, we need to establish a admin panel for this bot, in the panel appears a custom field to fill in order to what question the bot attend to and what answer the bot shows when this word or sentence activate the trigger, a simple field with "fill with the trigger sentence or word", after of this field a dropdown menu that let the admin select between "simple answer" or "custom answer" in the simple answer the admin only put text, in the custom answer the admin can put php code (this is for the mathematics for example, the bot needs to discompose the sentence and work with each part), i need to the demo have the example with the mathematics and the following examples: 1) Make a post in a list of groups of Facebook 2) Where is a restaurant near? 4) can you please translate "this" to German? 5) Make a post in the fanpage using one word of the sentence and tag the Facebook user We need to implement this bot in a couple of fan pages, so i need to the code be ready to modify and easy to understand.