Matlab/Parameter Dependent System/Gain scheduling H infinity Controller/Smult and Sdiag Command -

i have 2 systems , want them interconnected in series

s=zpk('s') sys1=(2*s)/(s^2+2*s+1) sys2=(2*s)/(s^2+3*s+2 

i want use sdiag , smult command because system parameter dependent. following error,

error using inputoutputmodel/subsref (line 43) use 2 or more subscripts select or delete elements, in "sys(:,:)" command.  error in islsys (line 10)         sys=sys(:);  error in sxtrct (line 13)     if ~islsys(p),  error in smult (line 65)         [a,b,c,d,e]=sxtrct(s1); 

i dont have idea error,

is can me please? best mostafa