controls on hotpoint ice diamond freezer?

bought an ice diamonf freezer second hand,works ok but havent got the hang of the lights or two switches for freezing or defrosting,need help please.From left to right. Sliding horizontal switch, which when slide to the right turns the first light of the three,orange. The middle light is green and is on all the time the freezer is on power. The third light is red but not on. The last control is also a slider but seems to do nothing when mved in either direction