jquery keypress event object keyCode for firefox problem?

jQuery keypress event for FireFox gives encrypted keyCode property for event object after String.fromCharCode(e.keyCode) conversion but works perfect in Chrome.

Following is the javascript code:

<!-- #booter and #text are ids of html element textarea -->

<script type="text/javascript">        
    $(function(){
        $('#booter').keypress(function(e){              
            var input = $(this).val() + String.fromCharCode(e.keyCode);
            $('#text').focus().val(input);
            return false;
        });
    });
</script>