The other way to do this is (let x as the maxium hitpoint of the unit):
Trigger 1
Looping: off
Effect0 Change object HP -x
Effect1 Damage object -1
Effect2 Change object HP x
However, if you DON'T KNOW the maxium HP of the unit or if it is a GAIA unit like tree, you can try:
Trigger 1
Looping: on
Effect0 Damage object 2147483648
Effect1 Damage object 2147483648
Effect2 Damage object 2147483648
Effect3 Damage object 2147483648
Effect4 Damage object 2147483648
Effect5 Damage object 2147483648
Effect6 Damage object 2147483648
Effect7 Damage object 2147483648
Effect8 Damage object 2147483648
Effect9 Damage object 2147483648
.
.
.
Effect1023 Damage object 2147483648
P.S.: Should you don't want to set up such a large number(1024) of trigger effects, you can ask the help of "timer" and "looping".
Both method will make the unit become invincible.(However, at some cases with the second solution, the unit or building won't have their hitpoint shown as 0/x.)
[This message has been edited by scenario_t_c (edited 02-28-2004 @ 02:13 PM).]