Spectator Ions – Ions which are not directly involved in the net ionic equation are called spectator ions.  In the previous equation, this would be the sodium and nitrate ions.
Ag+1(aq) + NO3-1(aq) + Na+1(aq) + Cl-1(aq)     Na+1(aq) + NO3-1(aq) + AgCl (s) 
Ag+1(aq) +   Cl-1(aq)      AgCl(s) 
(Net Ionic Equation)
Ag+1(aq) + NO3-1(aq) + Na+1(aq) + Cl-1(aq)     Na+1(aq) + NO3-1(aq) + AgCl (s) 
(Spectator Ions)