JavaScript - how to create files with javascript for chrome browser?

I have used the coding CreateTextFile(fname, true). but it doesn't work. so pls help me.........

The browser will prohibit you from writing files to the hard drive of your visitor using Chrome, FireFox, or IE (or any other browser for that matter).  If the text is small enough, you could stick it in a cookie for persistence.

Are you trying to save the file to the server or on the client?