Plotting multiple line on Matlab but only last plot showed

Below is my code. I would like to have two lines show on the same plot, but the code below only plot the very last plot command. Can you advise me what I need to change to get the code to have two lines show, one for v_trace1 and second for vtrace2 on the same graph.

Ia = 1.5; Ib = 1; C = 2; R = 10; tau = R*C;

tstop = 200; % ms

V_inf = Ia*R;

h = 5;

V1 = 0; V_trace1 = [V1];

V2 =0; V_trace2 = [V2];

for t = h:h:tstop+100

   % Euler method: V(t+h) = V(t) + h*dV/dt
   V1 = V1 +h*(- (V1/(R*C)) + (Ia/C));
   V2 = V2 +h*(- (V2/(R*C)) + (Ib/C));
   % Stop current injection 
   if (t == tstop)
     Ia = 0;
     Ib = 0;
   end

   V_trace1 = [V_trace1 V1];
   V_trace2 = [V_trace2 V2];

    plot(0:h:t,V_trace1,'r')
    plot(0:h:t,V_trace2,'r')
    axis([0 tstop+100 -V_inf V_inf])

end

Answer 1

[Azzi Abdelmalek]

    plot(0:h:t,V_trace1,'r')
    hold on
    plot(0:h:t,V_trace2,'r')
    figure

Answer 2

[Wayne King]

Hold the plot on:

 Ia = 1.5; Ib = 1; C = 2; R = 10; tau = R*C;

 tstop = 200; % ms

 V_inf = Ia*R;

 h = 5;

 V1 = 0; V_trace1 = [V1];

 V2 =0; V_trace2 = [V2];

 for t = h:h:tstop+100

   % Euler method: V(t+h) = V(t) + h*dV/dt
   V1 = V1 +h*(- (V1/(R*C)) + (Ia/C));
   V2 = V2 +h*(- (V2/(R*C)) + (Ib/C));
   % Stop current injection 
   if (t == tstop)
     Ia = 0;
     Ib = 0;
   end

   V_trace1 = [V_trace1 V1];
   V_trace2 = [V_trace2 V2];

    plot(0:h:t,V_trace1,'b'); hold on;
    plot(0:h:t,V_trace2,'r')
    axis([0 tstop+100 -V_inf V_inf])

 end