Need some pagination help

[MWE_001]

I been working on a little something on the side. A minor mod. My first ever. I ran into a small snag that is just aching my back bad.

I have a userlist built in to it and when I click to sort users by Username ascending, It allways reverts back to the original setting that was set default in the database like for example, Usernames Descending. I would like it to stay the same from page to page until I get out of that screen or until I change it what ever needs to happen. reselecting every single time i click page 2 page 3 etc is just killing me.

Any suggestions from you php Gurus? <img>