Small NPC Help please

[wildwog2001]

I made a small npc so as long as the player had this npc in his/her inventory they could say like /add 10 gralet etc..... yet i dont know how to do it so that its if the player has the weapon, i knowh owt o do it if its weaponfired but not by chat if they are holding the weapon yet i can do it while it is on the ground somewhere in the level. can anyone please explain to me the certain commands I can use to get it to work for when the player is holding the weapon.