no error???? why???

[Shuchi Agrawal]

i m using Qt4.2.2 evaluation version.
following are my files in a project
in 7th line of form.cpp i m calling ui.disp() and
on line no. 13 in function disp() i m calling QmessageBox..
my ques is that why its not giving error during compile.
i m using nmake1.5 n winXP n Visual studio C++ 6.0.
plz suggest me better programming in my given code..

can any1 help me to draw a line or anything on the central widget when i click a menu item?
thanks in advance