Encoding strings to unicode? HELP MEEE!!!

Can somebody help me?? Please I need a function in php which can encode regular strings (any kind of characters) to their unicode code. The problem is that i need it very quickly... i spend many nights but i didn't managed to resolve it. Althought i managed to create a function which can decode from unicode encode to the regular string.. (like &#38 -->"&").
So can anybody help me, i need it at school.... HELP MEEE!!!!!!!!!!!!!!!

 

Try these pages:
UTF-8 in PHP
Character set and character coding issues in PHP

 

Quick FYI: & --> & is NOT unicode decoding, it's entity decoding