I know that clicking on:
<a href="http://www.example.com">Click here</a>
would quit the current page and go to this address, and that
<a href="http://www.example.com" target="_blank">Click here</a>
would open it in a new tab (default behaviour in Chrome and Firefox).
But how to have a button such that clicking on it would open the external website in a new browser window, possibly 700x500px? (like if you do New window in Chrome menu)