Custom behavior on ASP.NET client-side validation

Let’s say you want to trigger special behavior when ASP.NET client side validation is triggered – something other than displaying an error message. In my case, I needed to change the border color of the offending control(s). There is no built in way to do this right now, so far as I’ve been able to […]

AJAX message could not be parsed

Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed. Common causes for this error are when the response is modified by calls to Response.Write(), response filters, HttpModules, or server trace is enabled. I ran into this while working with an UpdatePanel. After a partial postback, the returned AJAX would trip that Javascript error. […]