Automatically add Line break in TextBox/TextArea using Javascript

like this :

<script type="text/javascript">
    function EnterEventDesc(e) {
        if (e.keyCode == 13) {
            var input = $("#messageBox");
            input.val(input.val() + "<br/>");
            return false;
        } else {
            return true;
        }
    }
</script>

 <input id="messageBox" onkeypress="return EnterEventDesc(event);"  type="text" />

dont forget to reference js file in your head section