The Marvel comic known as XSE, or Xavier's Security Enforcers, was created by Whilce Portacio, John Byrne, and Art Thibert. The XSE is a team of mutants that is determined in catching criminal mutants.
The airport code for Sebba Airport is XSE.
Teach to a Pokemon in your party that is able to. When you're in a dark area, open your party and select the Pokemon that you taught it to. 'Flash' should come up in the options, just press that.
Look up PKSVUI. It it awesome. It has a script generator so you don't have to type in all that crap I use XSE. Dude! Its VERY easy to use!
You can download Extreme Script Editor (XSE) from various websites that host ROM hacking tools, such as PokéCommunity or GitHub. Be sure to download it from a reputable source to avoid any potential malware.
This is a very common thing with this program. I too have had trouble with it and decided to use another one. I recommend A-Maps and setting up XSE script editor as the main script editor and trying things from there.
16923E is the offset. It's a level script which means thats it's in the map, not the person. The level script is located in the header tab in advanced map.