Trying to set a checkbox here and i'm going loco

[eluser]sandwormusmc[/eluser]
I would say avoid using empty() altogether. There's some good comments on it at PHP.Net regarding why it's not good in all cases (here).

I've been using strlen() to test for null values ... try that and see if it works. If it doesn't, assign that user_data information to a variable first, then test it. It's important to note what walesmd pointed out, that user_data() is a function, not an array. I think what empty()'s shortcomings are in this case are that it doesn't evaluate the function return value, and thus the errors you're seeing.