yes this is valid test case because by this we try to check
nature of application for NULL value.

Yes This is a valid Test case.

Yes. We have to verify Login operation by leaving blanks in 
both fields. Alert message should be appeared. It should 
not allow to next page.


Nuthan Kumar V
Testing Engineer.,

Yes this test case is a check for boundary value condition
of NULL in both fields. This test can tell if the proper
error messages are displayed (checks error handling
techniques used in the code). Moreover it also tells if
these conditions are 

--> handled in the front end - by having javascript code and
displaying alert boxes
--> handled by backend - by displaying error messages on the
web page. These types of errors for field validatios can put
extra load on the server.