PHP based Spell check control

I am developing a web site where i need to accept data from user. What i am looking at is some spell check where as an开发者_StackOverflow社区d when user types it shows the suggestion. Like the box we use in while type the question in Stackoverflow.

It should be based on PHP. I am looking free opensource which i can use in my project.

Do you want to correct the spelling of the input or provide a list of choices based on the user's input (aka auto completion)?
These are two different things.

If you really mean a spellchecker, Ajax Spell Checker could be what you are looking for. It uses Ajax and PHP and needs either pspell or aspell.