function poly=poly_add(poly1,poly2)
   N1=length(poly1);
   N2=length(poly2);
   if N1>N2
       poly=poly1;
       for h=1:N2
         poly(h)=poly1(h)+poly2(h);  
       end;    
   else
       poly=poly2;
       for h=1:N1
         poly(h)=poly1(h)+poly2(h);  
       end;
      
   end;