What do you mean by 'open PDF' files using Javascript? You need the appropriate softwares for opening the respective files e.g. Acrobat reader for PDF files. The maximum you can do is make the browser open up a prompt box which would give you the option of either saving the file to your local system or opening it with a program of your choice and this can be done using plain HTML; no javascript required. Browser embedded Javascript is as such not capable of *reading* files.

hi,
thanks for ur response. whatever u said is correct but its not solve my problem. i have already done like that. i need to open the application using java script. its my requirement.
my file download popup should not come. and no files should be download in the local machine.
the files should be fetch from the server and it should open in its corresponding local machine.
i trust u can understand my problem. pls help me S.O.S....
Advance thanks
hidash.

Javascript can't spawn processes and it's a part of the browser security model; you can't do anything about it. Maybe VBScript might have something in store for you, but then again, your application won't work for non-windows users. Your best bet would be to set the appropriate mime type (content type) of the response and hope for the best.