Research on the input button function of JavaScript-type file

Like http://www.youku.com/v1.0.0326/v/swf/up.swf
This is Youku's video upload option. It does not display non-video files through flash.
The flash effect is generally described here. CopyCode The Code is as follows: Import flash.net. filereferencelist;
VaR fileref: filereferencelist = new filereferencelist ();
VaR alltypes: array = [];
VaR browsing type: Object = new object ();
Browsing type. Description = "browsing type (*. mp3 )";
Browsing type. Extension = "*. MP3 ";
Alltypes. Push (browsing type );
Fileref. Browse (alltypes );

Therefore, can we limit the file type in the pop-up window for our webpage <input type = "file">?
The solution is to use monitoring to remind users that the format of uploaded files is incorrect.<Input type = "file" name = "path" onpropertychange = "check ()"> (only jpg or GIF images can be uploaded.) <br/>
[Ctrl + A select all Note: If you need to introduce external JS, You need to refresh it to execute]

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[Ctrl + A select all Note: If you need to introduce external JS, You need to refresh it to execute]

However, this effect is obviously not as good as the flash user experience. It is necessary to pay attention to this type of Flash upload.