PHP, prevent javascript from running /delete javascript or php code written by user in a form [duplicate]

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• How to prevent XSS with HTML/PHP? 5 answers

I am making a website where people will publish an article. I make them write their article in a textarea, but I don't want them to add javascript, php or any other langage than html to prevent XSS or SQL injections. I'm trying to delete javascript or php code written by user in a form How can I do this?

via Chebli Mohamed