I have just bought of E-bay an unused ( unwanted gift ) Parkside SDS+ hammer drill. on reading the instructions I am a bit confused a bout the Drill/HammerDrill/Chisel selector switch. it says for chiseling select position C . The chisel is not locked . or turn the switch to position D . The chisel is locked in position. What is the difference ?. What happens in either of the two positions. has any body any idea , i dont want the chisel shooting out the first time I use it. Many thanks in advance. Dean.