PIcking units as varibles

Ok I have been trying to pick units as varibles in many occasions but it doesn't seem to work:\\ . Example : TRigger unit dies, now you go into the place where the unit should be and and it is grey and says no varible of this type. But beside it , it says Select A Unit so i click and it sends up the tool palette and when I click on the unit I want nothing happens/ double click/ triple click/ HUGE AMOUNTS OF CLICKS.....nothing happens

Thanks for your help, reply asap please:o

this shouldnt really be in the JASS forum. but anyway:

you cant select variables in regular events. you have to use an action called:

Trigger - Add Event

in that action you select the event you want to add and then to what trigger to add it to. In this event you can select variables.

Im not trying to pick a variable but a UNIT.

You must select a unit in World Editor not in the unit palette ( Thats for unit types ).

If you want the trigger to run whenever any unit dies, don't use a specific unit event, use a generic unit event. If you want it to work only whenever a unit stored in a variable dies, make it a generic unit event and add a condition that checks if the dying unit is equal to the unit stored in the variable.