Code needed for new website.

I need something like "Twitter" but not "Twitter" basically, i need a simple page where one can post a message for others to see. the message would be posted on the home page, but in order for others to read the message, they need to enter a password. then when the password has been added, the mesage will automatically delete within a x amount of time. (think mission impossible) please contact me for more questions. unitedvisionary@[login to view URL]