This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
I feel that both are correct but the first one is more appropriate. While second one is kind of a facility to add your own header and if the header about to be set already exist, it would override the value for that header.
Work Hard, Expect The Worst...<br /> <br />Bimal R. Patel<br />(SCJP 1.2, SCWCD 1.4)