submit form with enter key that has button in it

submit form with enter key that has button in it

I need to submit the form with the enter key, but it is not like the other
questions in this website in my case. I do not have a
input[type="submit"], but I have a button (<button id=""></button>).
The full code of my form:
<script type="text/javascript"
src="http://code.jquery.com/jquery-latest.min.js"></script>
<script src="js/my_script.js" type="text/javascript"></script>
<form id="myForm" action="userInfo.php" method="post">
<textarea name="mesazhi" cols="35" rows="4"></textarea>
<?php $idiperdoruesit = $_SESSION['id']; ?>
<input type="hidden" name="idiperdoruesit" value="<?php echo
$idiperdoruesit; ?>" />
<br /><button id="sub" style="border-radius:0px; border-size:2px;
border-style:solid; border-color:#ffffff; border-width:thin;
background-color:#000000; color:#ffffff; height:26px; width:60px;
font-size:16px;">Send</button>
</form>
When the user clicks the button Send, then a jquery function sends the
message to the database without reloading the page. Below is the jquery
function:
$("#sub").click( function() {
$.post( $("#myForm").attr("action"),
$("#myForm :input").serializeArray(),
function(info){ $("#result").html(info);
});
clearInput();
});
$("#myForm").submit( function() {
return false;
});
function clearInput() {
$("#myForm :input").each( function() {
$(this).val('');
});
}
How can I make to send the message by pressing the enter key?