Code a 'keep me logged in' option (eyelog)

We have an existing PHP site with a MySQL database. The whole site, including the login script, has been coded already. However, the client has now requested an infinite login option so they don't have to keep logging in. Please read through the attached document for full details of the job. The document password is securepass You will be given ftp and Cpanel access to complete the job. Feel free to ask any questions you might have.