Google Pagerank (PR) checksum function in PHP

We want a function (or class) written in PHP which generates and returns the Google Pagerank (PR) checksum for a submitted URL, needed for requesting Pagerank codes. (The checksum is individually generated for each URL and is submitted by the parameter "ch=1234567890" in any Google Toolbar request. Please bid only if you've already solved the checksum calculation/algorithm and tested it.) The function/class only needs to generate and return this checksum, all other types of Pagerank requests, API calls etc. are NOT needed. Your code should include complete documentation on how you achieved it, and in-line documentation for another programmer to follow and extend. Please state if you will deliver updates for this code, or not, in case of checksum/algorithm changes by Google - and for what duration after this first delivery. If there are additional costs for these updates, please state them, too. Only solutions in PHP are needed, please no "closed source" or compiled PHP (i. e. Zend, IONCube etc.). We need this code within 3 - 4 days after the bidding is closed. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Any PHP-compatible platform (i. e. Linux, Windows, *BSD etc.).