How can i express B'(1) in the code ? this code is for Tranparent Boundary Condition !

%initial condition

A=zeros(N,1);

B=zeros(N,1);

C=zeros(N,1);

D=zeros(N,1);

%with TBC LEFT-hand

gammaL=E(1)/E(2);

dsolve(B(1))=(-alphaw*ones(N-1,1))*gammaL+(-alphax*ones(N-1,1)+4*1i*beta/h+k^2*(n2(1).^2-n0^2));

C(1)=-alphae*ones(N-1,1);

D(1)=alphaw*gammaL*E(1)+(alphax+4*1i*beta/h+k^2*(n1(1).^2-n0^2))*E(1)+alphae*E(2);

%with TBC RIGHT-hand

gammaR=E(N-1)/E(N);

A(N)=-alphaw*ones(N-1,1);

dsolve(B(N)) =-alphae*ones(N-1,1)*gammaR+(-alphax*ones(N-1,1)+4*1i*beta/h+k^2*(n2(N).^2-n0^2));

D(N)=alphaw*E(N-1)+(alphae*gammaR+alphax+4*1i*beta/h+k^2*(n1(N).^2-n0^2))*E(N);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

A=-alphaw*ones(N-1,1);

C=-alphae*ones(N-1,1);

B=-alphax+4*1i*beta/h-k^2*(n2.^2-n0^2);

for p=2:N-1

D(p)=alphaw*E(p-1)+(alphax+4*1i*beta/h+k^2*(n1(p)^2-n0^2))*E(p)+alphae*E(p+1);

end

[Torsten]

We have absolutely no clue what the problem is and how you try to solve it. So how should we be able to help ?