Any link accessed by a button would move the viewer immediately to another site - even just clicking on the browser Home button but perhaps the Home button on a menu bar is not easily visible on a phone-based website with a small screen.
In which case put a small button at the top left corner of your web page with position: fixed (IE6 does not support position: fixed but at the top left corner it should behave like position: absolute) and link to whatever site you want. The button should always be visible except in IE6 which will scroll the button out of sight.
<div style="position: fixed; top:0; left:0;"><a href="google.com"><img src="button.jpg"></a></div>
You can google for free buttons, like these sites:-
http://www.freebuttons.com/index.php...onName=Classic
http://www.aaa-buttons.com/html/round.shtml
Code downloaded to my PC will be deleted in due course.
WIN7; IE9, Firefox, Opera, Chrome and Safari for Windows; screen resolution usually 1366*768.
Also IE6 on W98 with 800*600 and IE8 on Vista 1440*900.