This paper is concerned with the problem given below $$ (1.1) ifrac{dx}{du_1(x,lambda)} + q1(x)u_2(x,lambda) = lambdau_1(x,lambda) 0 leq x < infty - ifrac{dx}{du_2(x,lambda)} + q2(x)u_1(x,lambda) = lambdau_2(x,lambda), $$ $$ (2) u_2(0,lambda) - hu_1(0,lambda) = 0 $$ where $lambda$ is a complex parameter and h is a non-zero complex number.