add_exit
adds the room exits
int add_exit(string direc,mixed dest,string type,string material)
eg add_exit("south","pathtonestroom","door");
valid exit types are:
"standard"
"corridor"
"plain"
"door"
"stair"
"hidden"
"secret"
"gate"
"road"
"path"
Don't use anything else :)
There's also add_dig_exit to add exits that have to be uncovered.
See also renew_exits if you do anything cute with adding/removing exits