Hi everyone,
I am a volunteer at a hospital that serves a poor neighborhood. We refer patients who come up to us to resources like food stamps, childcare centers, public housing etc. We find that one major problem we face is inconsistency with our own referrals. Sometimes different volunteers facing the same issue will make different referrals.

In order to rectify this problem, we are compiling a decision tree that will prompt users questions related to housing for example, such as:

1. Does the client have HIV? Yes/No

If Yes: The web page will show resources that offer housing help for HIV clients.
If No: Other Questions will be prompted.

Of course our tree is more complicated than this. We would like to put this "decision tree" online, but I have no idea what coding language it should be done in, and if there is already free software that does this?

Thank you for reading such a long post!
Our clients really need this help. Thank you!

Any server side code can be used to create such a system

my approach for this will be...

extjs -- for user friendly, prsentable interface
ajax -- for faster interaction client to db
mysql -- backend db
php -- server side script

just as an afterthought (24 hours later )

This would fall into the "Expert System" mould I would suggest. Maybe it's worth looking up expert systems and seeing if there is something that looks appropriate for your needs.

I would suggest hiring someone to put this together for you if you don't know what you're doing. Call it a company expense.

You can find some designers here on the forums who might take up such a project for you, or you can check out: http://e-lance.com