Warp Point end of turn scripting option

OK,
I think I can do my warp point auto closure in another manner: using the Script_Main_ExternalEvents.txt to script in auto closure of all warp points.

My question and cry for help is: what is the script code or function call to close all the warp points at end of turn? And if all the warp points are closed at end of turn will the (if written into AI correctly) AI empires be able to open and transit through warp points during thier turn sequence?

I have looked through the script manual and the Script_Main_ExternalEvents base file and it doesn't look that bad to modify. I understand programming languages and how they work (been awhile sense I programmed though) but this is not a familiar structure to me.