[NEED HELP] NetRadiant Weapon Respawn

How can I make a weapon in Netradiant respawn only if it is not being held. i.e. I pick it up use the ammo, but it doesn't respawn until I die and the weapon disappears or until I drop it and then it disappears, I need this to make a balance in my map. it needs to wait 15 seconds after it disappears to spawn.

OMG!!! I never knew that. NO, I knew that i'm saying it only respawns if it is not being held, read back what I said this did not help at all.