what kind of webserver are you using? IIS6/7/8? Cassini, IIS Express?
You'r alerts gets fired? (alert('Error : 465/468'))?
You are posting HTML. That is a possible security issue in IIS. IIS will not accept html posted to server due to validation/security.
Your server will return "Potentially Dangerous Request.Form Value Was Detected From The Client".
<pages validaterequest="false" />
to your web.config.
And (if you are using .net 4)
<httpruntime requestvalidationmode="2.0" />
Your server is returning some sort of error-message. You can use IE Developer tools (F12) to see what the server is responding, or Chrome Dev Tools (also f12) to see what is sent to and received from server.