Q:

stop asking for download an embedded file on unavailability of plugin to display

I'd embedded a pdf file on my page. On some browsers it shows properly that pdf file but on some browser instead of showing that file it ask me to download that file.
One of the possible reason could be unavailability of plugin in the browser to display the file.
But I want that if it was unable to show do not ask the file to download.  
URL for reference

A:

You can use the https://docs.google.com/viewer to accomplish this.
All you do is enter the link and it wil generate a link
Use an iframe with that link to get it embedded

