Synonymizer/Spellchecker

Synonymizer/Spellchecker: I need a PHP+Javascript script that would do the following: (1) Correct the spelling, grammatical, lexical errors in text (similarly to what Word spellchecker does). In addition to standard checking i will add more simple rules. (2) Offer synonyms like a typical English synonymizer. (3) Edit/save text using the suggestions from the synonymizer/spellchecker. * I should be able to add new words/rules for synonymizer/spellchecker. **It will need to have a pretty but simple interface (I’ll forward the details).