I am an international student of University of California, Irvine, I want to extend the expiration date of my FI visa..

Hi, I am an student from China who is taking the graduate course here in University of California, Irvine. My F1 visa will expire this summer, but my education career will last for two year, therefore I have to go back to China and extend the expiration date, which is not convenient, would you please do me a favor to extend my F1 visa to the end of my graduate study career, which is the end of 2013 July. Thank you very much!