Link won't work Options

[RowanB]

I have a web page with a Log Out link on it. The link doesn't work. You click it and nothing whatever seems to happen. This is the section of HTML that creates the link (actual link shown in bold italic):

<form action='http://choir-stmaryssaffronwalden.org/change_role.php' method='POST'>
<input type='hidden' name='return_url' value='welcome.php'>
<p class='header' style='margin-bottom: 0px; margin-top: 0px;'>
Logged in as Rowan Sylvester-Bradley in role <select name='Role' class='header' onchange='submit()'>
<option value='1' selected>Member</option>
<option value='2'>Manager</option>
<option value='3'>Guest</option>
<option value='4'>Tester</option>
<option value='5'>Developer</option>
</select>
. <a class='link' href='http://choir-stmaryssaffronwalden.org/logout.php'>Log out</a>
</p>
</form>
<form action='http://choir-stmaryssaffronwalden.org/change_build.php' method='POST'>
<input type='hidden' name='return_url' value='welcome.php'>
<p class='header'>
Using build <select name='Build' class='header' onchange='submit()'>
<option value='20'>20 (obsolete)</option>
<option value='21'>21 (obsolete)</option>
<option value='22'>22 (obsolete)</option>
<option value='23'>23 (obsolete)</option>
<option value='24'>24 (obsolete)</option>
<option value='25'>25 (obsolete)</option>
<option value='26'>26 (obsolete)</option>
<option value='27'>27 (obsolete)</option>
<option value='46'>46 (obsolete)</option>
<option value='47'>47 (obsolete)</option>
<option value='48'>48 (obsolete)</option>
<option value='49'>49 (release)</option>
<option value='1000'>1000 (devtest)</option>
<option value='10000'>10000 (devtest)</option>
<option value='99999' selected>99999 (development)</option>
</select>
</p>
</form>

If I right click on the link, click Copy Link Address, paste it into the browser address bar and press Return, then it works fine. How can this be? What is the difference between clicking a link, and pasting its address into the browser address bar and pressing Return?

Thanks - Rowan