how do u check if src is a player

if(src.client.key != null) ?

A player is anyone that has a client(well unless you can have people join that aren't technically players).

So all you have to do is

if(src.client) //If client is null then src is not a player.
//src is a player
else
//src is an NPC


But depending on the proc src might not be a mob so make sure you know where to use it.

BTW: This should be in Newbie Central.