Protecting contents by entering password

[kiki00wong]

Hi everyone

I would like to protect my web materials by setting up a simple programme which require first-time visitors to sign up a simple form (register) first.
This is supposed to record the user, for webmaster's refernece.
Then an e-mail is sent to the visitor's e-mail account, containing a download password that can be used to download materials on my site.
The password is set by the master and it could be change.
There is a simple form uder the download page, for user to enter the download password and then you can access the download correctly.

I know I explain badly, so I attached this site to you (http://www.hsiu28.net)
I saw this programme in the "web material" area.
Never mind the chinese.
The blinking words in the center of the web material page is registering.
And after you receive the password, you go in different zone,
find the desired materials, enter the password in the field read "pass"
then press "down#x", and you can download.
The master tell me it works with Php and she download it here.

Sorry for the annoyance.