In this study, an interactive Graphical User Interface (GUI) application was introduced and tested. It worked as a utility program to facilitate and maximize the re-use of existing FORTRAN software. The GUI had been designed to generate tabulated seismic data (e.g., coefficient of reflection and propagation wave velocities: P-wave and SV-wave), in order to perform investigating the wave propagation in fluid saturated poroelastic medium, through using a simple two-dimensional soil-structure interaction model. Additionally, the theoretical background was also involved. The output data was of interest for understanding the effects of water saturation on the response of the ground and building structures to some degree earthquake excitation. Furthermore, the GUI application provided several utilities (e.g., viewing and plotting capabilities, file manipulation, editing as well as cloning the input parameters). Operating systems for which program had been designed were Windows XP, Windows Vista, Windows 7 and any (32) bits windows. The compilers were: Microsoft VC++ VS 6.0, Digital Visual FORTRAN 6.0 and Borland C++ Builder 6.0. The produced source code could be considered as successful case study for software engineers GUI developers, who were interested in creating (C++ /GUI), for FORTRAN by using the experience of such open source codes.