Anyone have a good script or function that cleans user input? I need to allow entry of URLs but ensure that no malicious code can be entered or run.

I wrote a quick little URL server header checker that allows multiple URLs, http and/or https, follows redirects and displays full headers or brief headers for each step in the redirection. I'd like to make a page available to the public, but I'm concerned about the security.

The design of the input form isn't critical; right now I allow for a comma delimited list of urls in a text area for entry of the list. I'm open to any manner of entry that will result in a good user experience and a list of URLs in my code.

Thanks.