When you change a deoxys form will it stay in that form forever?

Question

Im wondering because welll im just curious

Answer 1

No, you can change it whenever you want,just go to the Meteorites in the southwest of Route 3 in HG/SS and in Vilestone City
http://www.serebii.net/diamondpearl/deoxys.shtml

http://www.serebii.net/heartgoldsoulsilver/forms.shtml

Answer 2

No, there is a rock that makes it normal form, one that makes it attack form, one that makes it defence form and one that makes it speed form. (speed form is one of the fastest pokemon ever!)
if you want to change deoxys's form you have to go to veilstone city (sinnoh) or to the left of cerulean city (kanto).