Change of status- F1 to H1 visa


I completed my Master’s and then got H1B visa(valid upto 2013 Dec) approved by USCIS and worked for sometime. I came to India for a vacation and unfortunatley got a 221g which is pending from quite sometime. I have now decided to go to US on F1 visa and then apply for change of status(COS) from F1 to H1B as my H1B is not rejected as of now and is valid upto Dec 2013. Is it possible for me to apply for COS? Please reply.