[Trigger] Making a unit die when entering a terrain

[Dimitri]

Well,first of all, i know this isnt the right place to post this, but I didnt find other one... well.
Im making a make like *Are u retard?*
But I cant make the trigger, to when a unit step on this terrain (Dirt), to kill the unit, i want this trigger for 10 units, im having too much trouble with thatl... could anyone help me?

Thanks in advance =)