Storing damage dealt in a variable

[bugbear]

What would a trigger look like if i wanted to store how much damage a unit dealt with a normal attack into a variable.

For example: My footman swings at a priest, he deals 10 damage. This damage is then stored into my X variable.

 

[WolfieeifloW]

You'd have to use a "is attacked" trigger.
Store the life of the unit into a variable.

Add "unit takes damage" to another trigger.
Store the units life into another variable in the takes damage trigger.

Minus the second variable from the first;
You have the damage taken.

This is somewhat unreliable however as the unit can take more damage between "being attacked" and taking the damage (ie. if the attacking unit is ranged) .