Multiplot

Hii

i am posting code with the warning message.can you please help me how to solve this?

%code for multiplotting
x=1:4*pi
y=sin(x)
z=cos(x)
k=tan(X)
plot(x,y)
hold on
[AX H1 H2]=plotyy(x,z,x,k)
r=cot(x)
s=sec(x)
hold on
plotyy(x,r,x,s)
legend('sinx','cosx','tanx','cotx','secx')

Warning: Ignoring extra legend entries. 
> In legend at 294

"secx does not appear in the graph"

also while zooming this curve does not get zoomed