This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
As far as my understanding, it all depends on the method you give in form tag..
So when you use onclick="document.someForm.submit();" for a hyperlink, it will submit the form using the method specified in the form tag..