Commonest reason for a "cannot find symbol" error message is a Tiny Spelling misstake, which is different from a tiny spelling mistake. Java recognises spelling and Spelling as different words.
John de Michele
Joined: Mar 09, 2009
Since you haven't declared a variable called 'frame' in your main() method, Java does not know what to do when you call frame.setDefaultCloseOperation(). You also are calling new FreelanceBillingUI() without assigning a name to it. Maybe this is where you were supposed to define 'frame'.
Joined: Oct 13, 2005
The GUI builder in NetBeans is really nice. Until you try to understand the code and realise you have learned nothing about layouts. Don't use automatic GUI builders at the "beginning" stage.