Blog, Chat, or other post fundtion on webpage

I need to add a funtion to an existing web page, preferably as an inline frame. It will be used for company-wide communications for a small firm (5 employees). It can look/feel like a chat window OR a blogger. It must retain history so that even if you unload the page and go back, you will be able to view what has been posted. Unless you have a better way, a text file is fine for saving the history. It should look like this: Lynn (09:14): I have to leave to go to the post office. Steve (09:24): I need to take an early lunch today. Lynn (9:42): I am back. As you can see, each post gets added to the bottom of the file. There must be an easy way to add a post, preferably with a small text input box where the user will type the message and press [ENTER] or click a 'post' button. This should be above or below where the information displays. The file contents need to be displayed on the page in a scrollable box. It needs to reload itself at specified time intervals (like 30 seconds). The number of seconds needs to be adjustable (perhaps stored in a configuratio file). When the screen reloads, the scrollable text box should automatically scroll to the end. If this is not feasible, the posts should be put in the file with the most recent at the top. The web page where this will be added is at [login to view URL] You can also see my 'miserable' attempt at doing this with a google blogger at [login to view URL]