embed object and no DL to browser cache

[ray]

i know this can be done, but i just couldn't figure out how. can
someone give me a hint or somthing?

it's a asp web application, and i need to use html tag "embed" to put
a pdf document on a web page. but i don't want the visitor to download
the embeded file. visitor can only view it in browser and the embeded
file will never sent to visitor's browser cache.

so, what's the tricks that i should do at server side to accomplish
this?

ray