How much balance difference

Hi,

i am reconciling AP to GL for AUG period (01-AUG-2013 to 31-AUG-2013) using below formula

Account Payables Trial Balance (APTB) as of 31-JUL-13 + Payables Posted Invoice Register(PPIR) for period of 01-AUG-2013 to 31-AUG-2013 - Payables Posted Payments Register(PPPR) 01-AUG-2013 to 31-AUG-2013 = Account Payables Trial Balance(APTB) as of 31-AUG-2013

APTB as of 31-JUL-13 = -150000

PPIR for AUG13     = DR - 810960 & CR - 1140930

PPPR for AUG13    = DR - 832000 & CR - 2000

APTB as of 31-AUG-13 = -500030

Now i would like to know how much balance having difference.

And also let us know what is the use of RECONCILE qualifier while defing natural account.