How do I add class to sidebar on $_GET

I got a problem to get correct class to my sidebar.

function sidebar_class($var) 
{
    if (isset($_GET['page']) == $var )
    echo ' class="selected"';
}

My URL will looks like

http://domain.com/index.php?go=users
http://domain.com/index.php?go=settings
http://domain.com/index.php?go=backup

My sidebar

<ul>
 <li<?php sidebar_class('users'); ?>><a href='index.php?go=users'>Users</a></li>
 <li<?php sidebar_class('settings'); ?>><a href='index.php?go=settings'>Settings</a></li>
 <li<?php开发者_运维问答 sidebar_class('backup'); ?>><a href='index.php?go=backup'>Backup</a></li>
</ul>

Now all my sidebar class being <li class="selected">. How to fix it?

wrong function... try:

function sidebar_class($var) 
{
    if (isset($_GET['go']) && $_GET['go'] == $var )
        echo ' class="selected"';
}

Do you want to check value of go instead of page. right?

function sidebar_class($var) 
{
    if (isset($_GET['go']) == $var )
    echo ' class="selected"';
}