How to plot phase potrait and vector field for a three dimensional ODE system?

System:

attempt:

if true
[x1, x2, x3] = meshgrid(-.1:0.08:0.1, -.1:.08:.1, -0.1:0.08:0.1);
x1dot =  x1; 
x2dot =  x2;
x3dot = -x3;
quiver3(x1,x2,x2,x1dot,x2dot,x3dot)

end

figure obtained:

Need help with this.