A warning for deleting submissions?

[Petie]

I'm not sure if it's actually not working it if your browser is just using a cached version of the script. I'll look into it but in the mean time, try CTRL + F5ing (Windows) a couple of times before trying it again if you have others to cancel.

Also, the prompt requires JavaScript so it won't work if you have it disabled and AdBlock has also been known to interfere with some site functions.

Edit:
Just tested and it seems to work fine for me so I imagine either JavaScript of AdBlock is your problem.