Change in Cost of Fixed Asset

sadguna chary (CA Final) (34 Points)

12 March 2009  
PQR ltd purchased a Fixed Asset from LTR ltd for Rs 100 (say), PQR ltd paid Rs 90 and retained Rs 10 as retainings. After one year,LTR ltd waived Rs 10, hence PQR ltd credited Rs 10 to P&L Account. Is the treatment of PQR Ltd is correct?, Is it required to alter the cost of the Asset.