Video clip on the map (adventure dialog).

Where should I enter the script? Should I select a neutral unit, press Space on it, then press Script?
Or should I go to Map Properties, select Script, and then Edit Script????

Only in Map Properties.

Can you take a look and see where I made a mistake? Here are the screenshots:

1. Did I write that the name of your hero should be in parentheses? The variable (in this case, hero) should be in parentheses. It should look like this:
function hello(hero);
if hero == "Talanar" then

2. Region names always go in quotes. As I understand it, you should have "unnamed 0" in both triggers.

3. In your second trigger, "unnamed" has only one 'n'.