For insert in a page, a URL for the unsubscribe user, I’ve used jJvascript.
For implement Javascript in the page, I’ve used this plugin:
Zia3 CSS JS
Where we can modify the page, I’ve insert this HTML line:
<a href="#" onclick="request()">Unsubscribe</a>
And, in the same page, in the text field “Zia3 Inline Custom Javascript”, I’ve insert this Javascript line:
function request()
{
var user= document.getElementsByName("nk")[0].value;
top.location.href= "http://name_of_site.altervista.org/wp-content/plugins/newsletter/do/unsubscribe.php?nk=" + user;
}
This is functioning.
(Sorry my English is not good)