[SOLVED] Custom Cvar Sliders in XGUI?

[Zotero]

Hi,
I'm running a TTT server (I know, ew, another TTT fag)
But I was wondering, in the XGUI menu, you know how if you go to settings, and then server, and on the side there's a slider for gravity? (and something else)
I would like to make a slider (or two) just below that, which changes a different cvar (ttt_spec_prop_rechargetime | ttt_spec_prop_force | ttt_spec_prop_base)
Thanks in advance!