Convert to unicode (mandarin)

I have a standard <textarea> HTML form field that captures input from end users. This input can contain any characters the OS/keyboard supports. I need to convert the submitted field of text into Unicode for delivery through a proxy. Without converting to unicode, the submitted field of text is garbled. This must be done in PHP. My specific interest is in converting Mandarin, but I will pay more for a programmer who can guarantee a broader language conversion. Ideally, the finished product is a single PHP file that first loads a <textarea> and SUBMIT button. Submitting the page will echo the <textarea>'s value in Unicode. ## 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 Linux; PHP 4.3.x; the data will be stored in a mySQL database, version 3.23.x. If updated versions of PHP or mySQL allow for simpler code I am open to paying for multiple solutions. Please make your recommendations.