I have

success: function (response) {                   
          jQuery("#message_" + Update_Parts[1]).html(response).fadeOut('slow');                               
 },

As part of an Ajax call

jQuery("#message_" + Update_Parts[1]).html(response).fadeOut('slow'); 

Works the first time but not if I click the button again without refreshing the page

The ajax works but I don't get a message showing. It is as thought "#message_" + Update_Parts[1] doesn't exist after the first time. What am I doing wrong? Thanks