In this article, flow of laminar, isothermal, incompressible electrically conducting viscous fluid is considered in a rectangular domain with infinite length and bounded by two orthogonally moving porous walls that enable the fluid to enter or exit during successive contractions or expansions. Problem's solution is approximated using Variation of Parameters Method (VPM). To investigate the effect of non-dimensional wall deformation alpha, permeation Reynolds number R and magnetic parameter M on the flow field, graphical results are presented. Analytical solution obtained by (VPM) is supported by numerical results and they both agree. The study of the flow between dilating or squeezing porous walls is drastic simplification of the transport of biological fluids through dilating or squeezing vessels.