I still have an expired I-94 White Card which I got it when coming back to US in 2005. The valid date on the card is 12/12/2006. Since then, I extend my H1-B based on approved I-140 and got the extension to 12/12/2009. The approved I-797 has a bottom part (I-94) which has the same number as the original I-94 I got in 2005 with the expiration date 12/12/2009. I got my greencard last year, I plan to travel out of country, do I need to surrender both I-94 cards or just the original expired white card? or I don't need to surrender anything since I already got the greencard?