When running user inputed Javascript, is there a way to detect and stop "problem" scripts?

Question

On a page, something like jsFiddle, that executes user inputed Javascript, is there a way to stop / disrupt "problem" scripts running in an iframe?

The major class of problem scripts would be infinite loops, I think. Browsers deal with multiple alerts quite well, but a script like, ​for (var i = 0; ++i; i < 100) { /* do stuff */ }​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ will go forever.

How can I either detect and not run, or run and stop, say after 10 seconds of running, a script?

Removing the iframe is fine, but I only want to remove it if the script is still running after 10 seconds, but I don't want to remove it if the script has stopped running.

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Here is how I imagine the page will work. If you have a better solution, let me know...

The input page contains a textarea and a blank iframe. The user enters their script into the textarea, and when ready they click on run. Then (backstage) a separate page is created that contains the user script in executable form on an HTML page. The src of the iframe is set to the page with the executable code. This all happens dynamically without a page refresh.

Answer 1

I haven't used this jsandbox script, but it appears to have what you want.

Answer 2

If one script freezes on a page, other scripts will not continue to run. Therefore, there is no way to detect if another script has stopped running, without using a custom plugin or something. Browsers do not use multithreading in that way.