Your page has two forms on it. change the form tag at line 323:
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post" name="subscribe" id="subscribe" onsubmit="WAValidateEM(document.forms[0].SubscribeEmail,document.forms[0].SubscribeEmail.value,'Please supply a valid email address',document.forms[0].SubscribeEmail,1,true);WAAlertErrors('','',true,false,false);return document.MM_returnValue" >
to:
<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post" name="subscribe" id="subscribe" onsubmit="WAValidateEM(document.forms[1].SubscribeEmail,document.forms[1].SubscribeEmail.value,'Please supply a valid email address',document.forms[1].SubscribeEmail,1,true);WAAlertErrors('','',true,false,false);return document.MM_returnValue" >