<script type="text/javascript">
    $(function()
    {
       var  testTextBox = $('#TestTextBox');
        var code =null;
        testTextBox.keypress(function(e)
        {
            code= (e.keyCode ? e.keyCode : e.which);
            if (code == 13) alert('Enter key was pressed.');
            e.preventDefault();
        });

    });

</script>