You haven't shown the code for button.
However you can do this by just using the HTML anchor tag, something like following-
<a href="http://www.w3schools.com">Visit W3Schools.com!</a>
Reference:
HTML a tag[
^]
If you want have button like appearance then you can try -
Without javascript:
<form action="http://www.w3schools.com">
<input type="submit" value="This is a button link">
</form>
With javascript:
<input type="button" value="This is button link" onclick="window.location.href='http://www.w3schools.com'">
Hope, it helps :)