Using onlinetime or something similar...

[Oxy-Moron]

I've been toying around with the idea of a sort of exp system based off of onlinetime, but I'm having some serious trouble getting any thoughts relative to this from my NATs.

In principle, a player would make a class, and when made, it would set a flag in their account equal to their online time. Then when the player goes to some sort of shop (we'll call it an exp. shop just for sanity's sake), the shop's script compares the player's current online time to the time in the flag. It would find the difference between the two and give the player exp according to that amount (calculation still to be figured). The shop would then set the original online time flag to the player's current online time.

As far as I've heard, there probably isn't a command for detecting online time, so is there any way possible, if this is so, that a system could be rigged to work LIKE this without having timeouts run for 60 seconds and adding on, to prevent lag? (Like Mithica's horrible EXP system).

Any help would be much appreciated.