Testing GUI Application :

GUI software testing is the process of testing a product
that uses a graphical user interface, to ensure it meets its
written specifications. This is normally done through the
use of a variety of test cases.
Most clients in client/server and web-based systems deliver
system functionality using a GUI. When testing complete
systems, the tester must grapple with the additional
functionality provided by the GUI. GUIs make testing systems
more difficult for many reasons: the event-driven nature of
GUIs, unsolicited events, many ways in/many ways out and the
infinite input domain problems make it likely that the
programmer has introduced errors because he could not test
every path.

Available literature on testing GUIs almost exclusively
tends to focus on tools as the solution to the GUI testing
problem. With few exceptions, papers on this topic pay
attention to GUI test design, but have concentrated on how
automated regression-test suites can be built and
maintained. One seminal paper on the subject formulates a
GUI test strategy to detect errors and use tools to assist
this process