How can I prevent a form from being submitted more than once

I recently found a huge security problem with my PM system that allows users to send a message as much as they want with a for loop in the address bar. Someone put this into the address bar:javascript:for(x=0;x<10000;x++)...

ASP.NET MVP vs ASP.NET MVC

My company is trying to make an informed decision about how to pursue future development.We seem to have narrowed down our future internal and external Applications to being web applications. But we are...