Creating basic PHP script to add lines to a webpage

[m0k1]

I'm predominately a Java guy, which is why I need some assistance on what I assume is rather simple to do in PHP (and rather simple with Java too, although perhaps a bit... verbose).Simply put, I want to construct a webpage which has a list of string items that users have added. At the bottom of the page would be a place in which a user could type "Hello World" in a box for instance and hit a submit button, adding it to the list of items. Adding to the top or the bottom of the list is irrelevant - I can probably tweak that later.I'm the kind of guy who doesn't just like answers, but at the same time I have no idea where to even start searching. I've done no PHP development before. What sorts of constructs or functions should I be looking at? I own the physical box it'll be running on (it's literally right next to me now) so permissions aren't a restriction, and neither is getting anything else that might help the situation (although I can't see how it would be needed for such a simple script). What sorts of input validation should I be really wary of? This service will be restricted to people who have be given access to a particular section of an apache-based website, so they have to log in to even see this planned page, but I'd like to cover all possibilities.Additionally, I would perhaps like output to look like\[quote\]"Hello World" added by user User1"This is an additional line" added by User2"Goodbye World" added by user User1\[/quote\]in the future. What should I be looking at to do this?Update to answer questions:When it comes to storage of the actual content, I'd be leaning towards a simple file holding each entry line by line, as Col. Shrapnel suggested. A think a database would be overkill, although I do have the wherewithal to implement it. If a user submits "Hello World!" then adding a line to a file that says \[quote\]"Hello World!" posted by User1\[/quote\]is sufficient.With regards to authentication, this is already set up in apache's \[code\]httpd.conf\[/code\] configuration file. Currently this allows access to a certain group of users through an \[code\]AuthGroupFile\[/code\] entry. This is where the script will be hosted. To access this script, users will have already authenticated themselves with their credentials. The authentication currently works for that section of the site. Really, this is a secondary concern of mine. It is enough that lines are simply added with no record of who said what. This is just sugar on the PHP cake if it can be done easily with what I already have implemented.