Do you mean, in the built-in PDF viewer, you want to remove icons from the black toolbar (or remove the entire toolbar) when other users open the file? I don't think that's possible... but someone else might have an idea.

You would still be able to print such a file via File > Print menu or print preview button. You can also easily save such a file to disk or use another application to handle these PDF files or even save the content as a screenshot and print the data that way.

may be some one can change the browser setting using javascript

If you want to control users from not being able to download and save, or print something that you post on the web, don't use the PDF format. Use something like dynamically generated PHP pages and float a transparent image over the page; that will prevent viewers from printing the page (along with preventing a screen capture) and from saving or downloading the generated page.

if its mandatory to use pdf formats then what should i do?

Here is a Bug report for document permissions. https://bugzilla.mozilla.org/show_bug.cgi?id=792816

(Please don't comment in that Bug report unless you can provide a patch to fix the problem.) https://bugzilla.mozilla.org/page.cgi?id=etiquette.html

If it's that critical, you could explore this partial workaround:

Use a script or configuration file on your server that changes the disposition based on the user agent. In other words, for Firefox, send an attachment disposition that forces a download outside the browser instead of the default (inline) disposition that allows Firefox to display the PDF in a tab.

Now... that won't stop the user from dragging and dropping the downloaded file on a Firefox tab to use the built-in PDF viewer, but most users would tend to open the file in their default viewer (e.g., stand-alone Adobe Reader).