thanx ahmad for rply........... my problem is that want to create one report so i did copy paste of all code of trial balance report which is submenu of pdf report of accounting module and i changed template id and template  action id in py file inside  wizard folder  and also changed menu action but it's giving error ...........

QWebException: "'NoneType' object has no attribute '__getitem__'" while evaluating
"data['display_account'] == 'all'"      

so can u help me how to solve this problem..