2 Triggerproblems!

1) how can i say a building that it should start producing a unit via Trigger?


2) i have a trigger, where i remove a unit, 20 seconds later there should be placed a new building at the same place of the removed unit!


how can i manage this?

1)Make a trigger with the action unit-issue train/upgrade order.
2)Make a trigger that removes the first, store ist position in a variable and then create a unit at the variable point.

can you give me the exact trigger?