blackbox.
because the application is tested as per the clients 
requirements witout involving in the internal logical 
coding.

Hi dear 
Black Box testing is most important bcause Black Box 
Testing is testing without knowledge of the internal 
workings of the item being tested.  For example, when black 
box testing is applied to software engineering, the tester 
would only know the "legal" inputs and what the expected 
outputs should be, but not how the program actually arrives 
at those outputs.  It is because of this that black box 
testing can be considered testing with respect to the 
specifications, no other knowledge of the program is 
necessary..
plz replay any body have doubts 
thankx