How to stop screen/session lock?

I use my laptop for multimedia connected to external screen and run it with the lid closed, well when I close the lid the screen locks and I have to plug a external keyboard in to type the password, what a pain and it would help a lot if I can turn off screen session lock. Anybody know how to turn it off? Thanks, -- Jimmy Johnson Devuan Jessie - TDE Trinity R14.0.4 - AMD A8-7600 - EXT4 at sda2 Registered Linux User #380263