No person may:
A violation of this section constitutes the crime of stalking. Stalking is a Class 1 misdemeanor. However, any second or subsequent conviction occurring within ten years of a prior conviction under this section is a Class 6 felony. Any conviction for, or plea of guilty to, an offense in another state which, if committed in this state, would be a violation of this section and occurring within ten years prior to the date of the violation being charged, shall be used to determine if the violation being charged is a second or subsequent offense.