IFRS Paper presentation!!! HELP needed urgent

Hi,
    I am having a doubt regarding comparatives in IFRS. During first time adoption of IFRS is it necessary to give comparatives also based on IFRS. I mean if a company is mandatorily required to prepare accounts based on IFRS from 1st April 2011 then whether the company have also re-prepare a financial statement for 2010-2011 based on IFRS or only adjustment in opening balances for 1st April 2011 will do good?