In free version 20 years didn't become website, by the way the operation of the business system demonstration hey format master record screen for MP4 format, as a demonstration operation,
HTML 5 code:
Your browser does not support HTML 5 video element,

There is nothing wrong with the code, in the development environment to play, but after the release, cannot play, no matter what browser is a screen, no content, thought it was playing the source path is wrong, but not over checking path problem, and MP4 are in the same directory page, then try some players, video save as, MP4 files can be found, but the download prompt again 404, file does not exist, suddenly thought of IIS the MIME type is not the MP4 format, check found was only MP2 format, then the new MP4 format, play normal, system is a sever 2008 RTM,
Such a small problem I spent a lot of time, later met need to download the code, it's best to see if the MIME support the format,