Checking a profile field's value and executing javascript

[Scandal]

Originally Posted by m0nde

Thank you. I'm not at all experienced in doing any of this.

--------------- Added [DATE]1461985905[/DATE] at [TIME]1461985905[/TIME] ---------------

In the end, in addition to my error with declaring instead of comparing values, I found that I needed to use $bbuserinfo instead of $memberinfo. I still don't understand when to use which.

You should use $bbuserinfo for the user who load the page.
If you need to apply code for the user of an item (for example on the postbit/postbit_legacy), you could use $post['fieldX'] (= it will return the fieldX value for the user of the post).