Service tax input tax credit

Dear all,

I am having one doubt on ST input tax credit. Earlier ST input was on cash basis. At that time a company had unpaid creditors. After making payment only they can avail input tax. So in books of accounts provision had made and ST input credit also shown( In 2010). After that they make payment to sundry creditors. But ST input tax credit had not availed in books of accounts. Can i avail now?? Since i had paid all my creditors with ST. Still now that ST input amount showing in my books of accounts. Is there is any time period to avail input tax crerdi in return?

Thank You,