One of the most important elements in the system development is the way the system provides an interaction with users through an easy to use graphical user interface. This paper introduces a method for testing systems and to evaluate the degree of usability for web-based systems. The method has been utilized in two phases and applied to the Emirates Airlines website as a case study. In the first phase a test is implemented on a number of users, and in the second phase the results acquired are converted into charts for the final web-based system evaluation. The results obtained were satisfactory. We have been able to identify the places where the weaknesses and gaps are, then we draw some recommended solutions to avoid them.