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.
you said: want to be able to submit this page to a servlet to get the forms values, at the same time as this I want to open a new window to display another page
I think it depends on what you mean by 'at the same time'. Is after form processing good enough?
So when the response page appears from the form submission, your second window could pop open.