UNSPENT CSR

Dear Friends,

It would b a great favor if any of u could help me with a query related to unspent amount of CSR ..

Q- The amount of CSR was 1 Cr. (just an example) out of which Co. spent 40 Lac only, will the unspent amount of 60 Lac be accumulated and added to next year's CSR amount or that would merely be shown in the books with reasons for not spending (In the Annual report as per Sec. 135)

If it should be accumulated and added to next year's CSR, can u cite any Law or rule that says so..

Thanks in advance!