Tds on lta

Dear Sir,

We have made provision for LTA of  one of our employee as on 31.03.2012 but still amt is not paid , employee will not submit any bills. we have not deducted/paid  tds on this LTA Amount.

My question is, whether we have to pay tds & shown in TDS Return of F.Y.2011-12 or TDS to be deducted on actual payment of LTA?

Please suggest

Thanks