<script type="text/javascript" language="javascript">
  function openExpress(){
      var url = 'https://www.paymate.com/PayMate/ExpressPayment?mid=<?php echo PAYMATE_USERNAME.
          "&amt=".$db->f("order_total").
   "&currency=".$_SESSION['vendor_currency'].
       "&ref=".$db->f("order_id").
      "&pmt_sender_email=".$user->email.
         "&pmt_contact_firstname=".$user->first_name.
       "&pmt_contact_surname=".$user->last_name.
          "&regindi_address1=".$user->address_1.
     "&regindi_address2=".$user->address_2.
     "&regindi_sub=".$user->city.
       "&regindi_pcode=".$user->zip;?>'
        var newWin = window.open(url, 'wizard', 'height=640,width=500,scrollbars=0,toolbar=no');
  self.name = 'parent';
       newWin.focus();
  }
  </script>
  <div align="center">
  <p>
  <a href="javascript:openExpress();">
  <img src="https://www.paymate.com/homepage/images/butt_PayNow.gif" border="0" alt="Pay with Paymate Express">
  <br />click here to pay your account</a>
  </p>
  </div>