Submit by javascript

Estou a fazer algo de mal para não funcionar este submit by javascript?

<?php
 echo '<form name="myform" action="data.php">';
 echo '<input type="hidden" id="x" name="x" value="'. $x .'" >';
 echo '<input type="hidden" id="y" name="y" value="'. $y .'" >';
 echo '<input type="hidden" id="events" name="events" value="'. $events .'">';
 echo '<a href="javascript: submitform()"><img id="myImgId" alt="" src="image.jpeg" width="' . $ver . '" height="' . $hor . '"/></a>';
 echo '</form>';
?>
 

<script type="text/javascript">
function submitform() {document.myform.submit();}
</script>