to read a xml file from disk using javascript

I have a xml file stored in my hard disk .i nee开发者_如何学运维d to read data from that alter and add some data dynamically. how can i do that?

JavaScript in the browser cannot manipulate files on the client's hard drive (except for cookies, if you really want to count those).

If there is ever an instance where the above is not true, something is seriously wrong and there exists a major security hole.