Need help creating trigger that damages units per second when they are in region

[BlackEnvyX]

Well basically on my map I have a lava section. I have four regions covering the whole lava area (so it's all covered) and I need a trigger that makes it so if a unit walks into any of these regions, he suffers 1 hit point of damage per second. (Units only have 50 HP on my map with no regen)
Can anyone help?

 

[deathismyfriend]

trig 1

event
. unit enters region ( ur region)
conditions
. unit is ground
actions
. add unit to group lavaReg
. if lavaBoolean == false
. then
. set lavaBoolean = true
. turn on trig 3
. else

trig 2

event
. unit leaves region ( ur region)
conditions
. unit is in group lavaG
actions
. remove unit from group lavaReg

trig 3
event
. every one second
conditions
. lavaBoolean = true
actions
. pick every unit in group lavaReg
. and damage unit for set damage
. if unit group is empty
. then
. set lavaBoolean = false
. turn off ( this trigger)
. else

 

[BlackEnvyX]

trig 1

event
unit enters region ( ur region)
conditions
unit is ground
actions
add unit to group lavaReg

trig 2

event
unit leaves region ( ur region)
conditions
unit is in group lavaG
actions
remove unit from group lavaReg

trig 3
event
every one second
conditions
actions
pick every unit in group lavaReg
and damage unit for set damage

+ Rep, thanks a ton! It works perfect!
Hey send me a visitor message mate I gotta talk to you about something.

 

[MortAr]

You can do all that in a single trigger, just every second check if the tile at each unit position is the lava one you use and simply damage them.