I couldn't get your method to work @Damien-at-SF...
So I resorted to my old knowledge.
By encasing the input type="button" within a hyperlink element, you can simply declare the target property as so:
<a href="http://www.site.org" target="_blank">
<input type="button" class="button" value="Open" />
</a>
The 'target="_blank"' is the property which makes the browser open the link within a new tab. This attribute has other properties, See: http://www.w3schools.com/tags/att_a_target.asp for further details.
Since the 'value=""' attribute on buttons will write the contained string to the button, a span is not necessary.
Instead of writing:
<element></element>
for most HTML elements you can simply close them with a trailing slash, like so:
<element />
Oh, and finally... a 'button' element has a refresh trigger within it, so I use an 'input type[button]' to avoid triggering the form.
Good Luck Programmers.
Due to StackOverflow's policy I had to change the domain in the example: https://meta.stackexchange.com/questions/208963/why-are-certain-example-urls-like-http-site-com-and-http-mysite-com-blocke