98 Grand AM GT: please help!!

I have a 98 Grand AM GT, Automatic on the floor...
on my shifter there is a button, when i push it in it says "GTS" on the dash.
I dont know what it means, or when i should have it on or off, and i dont have a manual...
Can anyone help me?

the button on the left side of the shifter is for the "ETS"...Electronic traction system or something like that! its function is simply to limit wheel spin in bad weather and loose gravel. And it needs to be off if u wanna make some smoke!

welcome to the forum frekey. Please don't ressurect threads older then 1 month.