Real time ajax chat in PHP PDO MYSQL

I need a realtime ajax chat build in php pdo. I already have a member site and I have the chat design ready, I just need someone to create a chat function to my current site. Well its two similar functions. One is a chat function which should have its own table on my mysql databse, the other is a notes function which is linked to each user on my members mysql database. Here is how the design looks like. [login to view URL] To the left is the realtime chat, where all my members should be able to chat with eachother in realtime, each added message should have the current date time, which user has written the message, for this function you can use the username session from my current site to grab the username. All the messages to the chat should be stored on my mysql database, but on site i only want to display the messages of the current date . And within the users form to the right there is a Notes tab where I want to be able to add notes. These notes should be linked to the particular user that is being displayed. forexample [login to view URL] should have it's notes, [login to view URL] should have its notes and so on. And to the right of the notes input field there are two checkboxes. These should have some predefined values, if any of them are checked the added note should have a predifined value added to itself. For example if the user adds the note: "Don't forget to visit that great site" and IS is checked, then the note should look like this on db notefield: "Don't forget to visit that great site" ISfield should then have some value on it and on site it should display like a note: "IS - Don't forget to visit that great site". For each note a current date and time should be added, the username of the persion who wrote the note (using my current username session to grab username), and also adding the level of the user who wrote the note (same here, we can use my current userlevel session from my current site to get this value).