I have this input of type \"file\", and I want to change its files list. Example:
For security reasons, browsers prevent javascript from changing the files which will be uploaded: only the user can select files via the user interface. This is to prevent an evil script to upload /etc/passwd, for example, without the user knowing.
The one exception is that calling "reset" on the form will clear the file or filelist, but you can never add to programmatically.
What you want is using the multiple attribute on the input element. That way, in newer browsers user will be able to select multiple files to upload.