Are you an absolute beginner to PHP? If so have a read at some beginner tutorials first and learn the basics, such as selection, iteration, variables, mysql, retrieving form data.
What you describe is a very simple web application, you could probably find a complete exampleof a guestbook if you search a bit.
Anyway, what I would recommend for this is a MySQL database to store the messages.
E.g. a table called 'posts' with columns: id (int), message (varchar), from (varchar), posted_on (datetime), ip_address (varchar).
PHP is very good at working with MySQL. Have a search for how to insert/retrive rows from mysql.
When retreiving the timestamp of the message, use the MySQL DATE_FORMAT() function to format the timestamp to hh:mm.
I would get it all working first, then add image verification (captcha), here's how:
http://www.php-mysql-tutorial.com/us...rification.php
Finally to get the time to live functionality, that depends on your hosting, is it a Linux server, windows?
If it's a Linux server, create a cron job, see 'crontab', that will call one of your PHP scripts after a specified interval e.g. every 24hrs which will run a query on the database to delete all the posts that are older than 24hrs.
If it's a windows server you can use scheduled tasks to do the same - however shared hosting may not give you access to this.
In answer to your question, yes it is very easy and very possible.
Hope this helps:wave:
