How to get username in Parent Portal

I need to be able to harvest the guardian username in the parent portal. I need to be able to dynamically control certain aspects of the page if a special group of users log in. I am not proficient in jQuery and I am really hoping that there is something like ~(username) that will show me the guardians username so that I could use it in a tlistSQL script. The timing on this is pretty urgent so I am hoping that someone can give me some guidance.

Thanks in advance!
Del Vogle