Hey! Question about making my code unexploited

[corb]

Hey guys!

I wrote a really simple php script, where a user enters their url, and that information is appended to an html file. Obviously, this is very vulnerable to injection code (you could inject javascript or maybe even some extra php).

I was wondering if there was an easy way to prevent injections. Like, could I put <noscript> tags surrounding the insertion point in the html?

 

Thanks ahead of time! (and if this already exists in the forum, please tell me the search I'd need to do to find it because I could find it)