could someone help ?

<p>I was recently taken off the waitlist for uc irvine and I do wish to attend, however I already SIR'ed to UCSB as a backup before May 1st. I know I have to withdraw my SIR to UCSB before i can accept the offer from UC Irvine, but here's my question: for UCSB, the statement to withdraw from the SIR must be handwritten and sent in a letter, if I write the letter, postmark it, and SIR to Irvine before the letter reaches the UCSB campus, will I be in trouble for SIR'ing to 2 schools ?</p>