Unhandled Error!

 
<form action="http://spreadsheets.google.com/formResponse?formkey=dFU0MzdsNUY3bG9MLVVRQ2xkellwVWc6MA" method="POST" id="myForm" target="hidden_iframe" onsubmit="submitted=true;">
<ul class="form">
<li class="field text left"><label class="" for="entry_0">Date</label>
<div><input type="text" name="entry.0.single" value="" class="text" id="date"></div></li>
</ul>
<input type="hidden" name="entry.1.single" value="<?= h($this->customer->first_name) ?>" id="entry_1">
<input type="hidden" name="entry.2.single" value="<?= h($this->customer->shipping_street_addr) ?>" id="entry_2">
<input type="hidden" name="entry.3.single" value="<?= h($this->customer->shipping_city) ?>" id="entry_3">
<input type="hidden" name="pageNumber" value="0">
<input type="hidden" name="backupCache" value="">
  <div class="clearfix"></div>
  <br />