How do you take a picture of your screen on the kin 2 windows phone from verizon?

[Sarah Loves you]

i have the Kin 2 windows phone by Verizon,and it ocasionally takes picture of the screen, i'm not sure if i'm hitting a button (if so what button(s)) or if it just does it by itself. i would really like to figure out how to take pictures of the sreen if thats even possible..So, do the Kin 2 phones just take random pictures when they want to, or do i hit a button(s) ? HELP!