JQuery Ajax Response Not Operating Correctly

The code below works "correctly" as far as sending the email address to the SaveEmail URL and it gets saved correctly each time I change the drop down. However it only outputs the "Successful" message once, no matter how many times I change the value in the drop down. The "data" that is returned is "Successful". I would like to show the message for a couple seconds, then fade it out. It works correctly the first time I change the drop down, after that the change happens and the value gets saved, but the "Successful" message doesn't display.

jQuery code:
$('#AgentEmails').change(function() {
var NewAddress = $('#AgentEmails').val();
$.post('SaveEmail.aspx', { email: NewAddress }, function(data) {
$('#SelectMsg').html("<b>" + data + "</b>").fadeOut();
});});

HTML code:
<select ID='AgentEmails' runat='server'>
<option value="test@test.com">TEST</option>
</select><span id='SelectMsg'></span>
What needs to be changed in my code to make this operate correctly?