<script>
$(document).ready(function(){
	var elements = ":input[readonly!=readonly]";
	$(elements).keypress(function(e) {
		var c = e.which ? e.which : e.keyCode;
		if (c == 13) {
			var index = $(elements).index(this);
			var criteria = e.shiftKey ? ":lt(" + index + "):last" : ":gt(" + index + "):first";
			$(elements + criteria).focus();
			e.preventDefault();
		}
	});
});
</script>