worked it out, forms with only one text field will submit on pressing enter, forms with more than one text field will not submit on hitting enter. the fix i used is putting this event on the single text boxes in my form
onkeypress="return noenter()"
calling this function
<script type="text/javascript"><!--
function noenter() {
return !(window.event && window.event.keyCode == 13); }
//--></script>
works perfect, it will no longer submit the form on pressing enter.