How can I detect when a map changes?

Garry's Mod coding
#1

How can I detect when a map changes so that I can run code once the map change is complete? This is while playing Half-Life 2 maps.

#2

**[Gamemode.InitPostEntity

http://wiki.garrysmod.com/favicon.ico](wiki.garrysmod.com/?title=Gamemode.InitPostEntity)**